Kevin sold a box of 28 books at a yard sale for a total of $54.64. He sold the paperback books for $1.68 each and sold the hardcover books for $2.44 each. Which system of equations can be used to determine the number of $1.68 paperback books, x, and the number of $2.44 hardcover books, y, that were sold at the yard sale?

A.
x + y = 28
1.68x + 2.44y = 54.64

B.
2.44x - 1.68y = 28
x + y = 54.64

C.
x + y = 28
2.44y = -1.68x + 54.64

D.
y = x - 54.64
1.68x + 2.44y = 28

Kevin Sold A Box Of 28 Books At A Yard Sale For A Total Of $54.64. He Sold The Paperback Books For $1.68

Answers

Answer 1

Answer:

A.  

x + y = 28

1.68x + 2.44y = 54.64

Step-by-step explanation:

Let x = paperback books and y = hardback books

x+y =28

We know that paperbacks cost 1.68 and hardback cost 2.44

1.68x + 2.44y = 54.64

We have 2 equations and 2 unknowns

x+y =28

1.68x + 2.44y = 54.64


Related Questions

Drag the tiles to the correct boxes to complete the pairs.

Match the graphs with the functions they represent.

Answers

Answer:

The parent function for a concave up parabola with its vertex at the origin is

y=a(x-h)^2+k.

+a points the parabola concave up

-a points the parabola concave down

h moves the vertex along the x axis that many times

k moves the vertex along the y axis that many times.

if you need more clarification comment on this question.

Answer:

The required functions are [tex]f(x)=x^2+3[/tex], [tex]g(x)=2x^2-3[/tex], [tex]h(x)=x^2-3[/tex] and [tex]j(x)=-2x^2-3[/tex].

Step-by-step explanation:

The vertex from of a parabola is

[tex]y=a(x-h)^2+k[/tex]

Where, (h,k) is the vertex of parabola is a is the vertical stretch factor.

If a is negative, then it is downward parabola and if a is positive then it is an upward parabola.

If |a|<1, then it is compressed vertical and if |a|>1, then it is stretched vertically.

The graph of f(x) has vertex at (0,3) and it is not stretch vertically so the value of a is 1. So, the function f(x) is defined as

[tex]f(x)=1(x-0)^2+3[/tex]

[tex]f(x)=x^2+3[/tex]

The graph of g(x) has vertex at (0,-3) and it is stretch vertically by factor 2 so the value of a is 2. So, the function g(x) is defined as

[tex]g(x)=2(x-0)^2-3[/tex]

[tex]g(x)=2x^2-3[/tex]

The graph of h(x) has vertex at (0,-3) and it is not stretch vertically so the value of a is 1. So, the function h(x) is defined as

[tex]h(x)=1(x-0)^2-3[/tex]

[tex]h(x)=x^2-3[/tex]

The graph of j(x) has vertex at (0,-3) and it is stretch vertically by factor 2 and it is downward so the value of a is -2. So, the function j(x) is defined as

[tex]j(x)=-2(x-0)^2-3[/tex]

[tex]j(x)=-2x^2-3[/tex]

Therefore the required functions are [tex]f(x)=x^2+3[/tex], [tex]g(x)=2x^2-3[/tex], [tex]h(x)=x^2-3[/tex] and [tex]j(x)=-2x^2-3[/tex].

The circumference of the circle is increasing at a rate of 0.5 meters per minute. What's the rate of change of the area of the circle when the radius is 4 meters?

1: 3 meters per minute
2: 4 meters squared per minute
3: 4 meters per minute
4: 2 meters squared per minute
5: 7 meters per minute

This is actually for a game but I'm really bad at math.

Answers

Answer:

The rate of change of the area of the circle when the radius is 4 meters = 2 meters²/minute ⇒ answer 4

Step-by-step explanation:

* Lets revise the chain rule in the derivative

- If dy/da = m and dx/da = n, and you want to find dy/dx

∴ dy/dx = dy/da ÷ dx/da = m ÷ n = m/n

* In our problem we have

- The rate of increasing of the circumference dC/dt = 0.5 meters/minute

- We need the find the rate of change of the area of the circle

 when the radius is 4 meters

- The common element between the circumference and the area

 of the circle is the radius of the circle

* We must to find dC/dr and dA/dr and use the chain rule to

 find dA/dr

- Find the rate of change of the radius dr/dt

∵ C = 2πr

- Find the derivative of C with respect to r

∴ dC/dr = 2π ⇒ (1)

∵ dC/dt = 0.5 meters/minute ⇒ (2)

- Divide (1) by (2) to get dr/dt by using chain rule

∵ dC/dt ÷ dC/dr = 0.5 ÷ 2π

∴ dC/dt × dr/dC = 0.5 × 1/2π ⇒ cancel dC together and change

   0.5 to 1/2

dr/dt = 1/2 × 1/2π = 1/4π (3)

- Find the rate of change of the area dA/dt

∵ A = πr²

- Find the derivative of A with respect to r

∴ dA/dr = 2πr

r = 4

dA/dr = 2π(4) = (4)

- Multiply (4) by (3) to get dA/dt by using chain rule

∵ dA/dr × dr/dt = 8π × 1/4π ⇒ divide 8 by 4 and cancel π

dA/dt = 2 meters²/minute

* The rate of change of the area of the circle when the radius is

  4 meters = 2 meters²/minute

The rate of change of the area of the circle when the radius is 4 meters is 2m²/min

How to calculate the circumference and area of a circle

The formula for calculating the circumference of a circle is expressed as;

C = 2πr

where:

r is the radius of the circle

The rate of change of circumference is expressed as:

[tex]\frac{dC}{dt} = \frac{dC}{dr} \times \frac{dr}{dt} \\0.5=2 \pi \times \frac{dr}{dt}\\ \frac{dr}{dt} = \frac{0.5}{2\pi} \\ \frac{dr}{dt} = 0.0796 m/min[/tex]

The change in area of the circle is expressed as:

[tex]\frac{dA}{dt} = \frac{dA}{dr} \times \frac{dr}{dt}\\ \frac{dA}{dt} =2 \pi r\times 0.0796\\ \frac{dA}{dt} = 2(3.14)(4)\times 0.0796\\ \frac{dA}{dt} = 2m^2/min\\[/tex]

Hence the rate of change of the area of the circle when the radius is 4 meters is 2m²/min

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How do the values in Pascal’s triangle connect to the coefficients?

Answers

Explanation:

Each row in Pascal's triangle is a listing of the values of nCk = n!/(k!(n-k)!) for some fixed n and k in the range 0 to n. nCk is the number of combinations of n things taken k at a time.

If you consider what happens when you multiply out the product (a +b)^n, you can see where the coefficients nCk come from. For example, consider the cube ...

  (a +b)^3 = (a +b)(a +b)(a +b)

The highest-degree "a" term will be a^3, the result of multiplying together the first terms of each of the binomials.

The term a^b will have a coefficient that reflects the sum of all the ways you can get a^b by multiplying different combinations of the terms. Here they are ...

(a +_)(a +_)(_ +b) = a·a·b = a^2b(a +_)(_ +b)(a +_) = a·b·a = a^2b(_ +b)(a +_)(a +_) = b·a·a = a^2b

Adding these three products together gives 3a^2b, the second term of the expansion.

For this cubic, the third term of the expansion is the sum of the ways you can get ab^2. It is essentially what is shown above, but with "a" and "b" swapped. Hence, there are 3 combinations, and the total is 3ab^2.

Of course, there is only one way to get b^3.

So the expansion of the cube (a+b)^3 is ...

  (a +b)^3 = a^3 + 3a^2b +3ab^2 +b^3 . . . . . with coefficients 1, 3, 3, 1 matching the 4th row of Pascal's triangle.

__

In short, the values in Pascal's triangle are the values of the number of combinations of n things taken k at a time. The coefficients of a binomial expansion are also the number of combinations of n things taken k at a time. Each term of the expansion of (a+b)^n is of the form (nCk)·a^(n-k)·b^k for k =0 to n.

Final answer:

The values in Pascal's triangle are the coefficients in the binomial expansion of (x+y)^n. Each row in the triangle represents the coefficients for a certain power of the binomial being expanded.

Explanation:

In mathematics, Pascal's triangle is a triangular array of numbers where each number is the sum of the two immediately above it. Each row of Pascal's Triangle corresponds to the coefficients in the binomial expansion of (x+y)n. For example, the third row of the Pascal's triangle is 1, 2, 1, which are the coefficients for the expansion of (x+y)2, yielding x2 + 2xy + y2. To put it differently, the values in Pascal's triangle provide the coefficients for each term in the binomial expansion. The index of the row in the triangle indicates the power of the binomial being expanded. So, effectively, the values in Pascal’s triangle connect directly to the coefficients in an algebraic binomial expansion.

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Question 5(Multiple Choice Worth 7 points)
Use graphs and tables to find the limit and identify any vertical asymptotes of limit of 1 divided by the quantity x minus 3 as x approaches 3 from the left.

∞ ; x = -3
-∞ ; x = -3
-∞ ; x = 3
1 ; no vertical asymptotes

Answers

Answer:

  -∞ ; x = 3

Step-by-step explanation:

The graph tends toward -∞ as x approaches 3 from the left. Thus there is a vertical asymptote at x=3, the value of x that makes the denominator zero.

Two cylinders, A and B, are mathematically similar. The height of B is twice the corresponding height of A.
 The volume of A is 13 cm^3. Find the volume of B.

Answers

Answer:

104 cm^3

Step-by-step explanation:

The ratio of volumes is the cube of the ratio of linear dimensions for similar figures. Since the height of B is 2 times the height of A, the volume of B will be 2^3 = 8 times the volume of A, so is ...

8·13 cm^3 = 104 cm^3

Answer:

The volume of B is 39cm³

Step-by-step explanation:

Volume of cylinder A

Va = 1/3πr²ha ...(1)

Where height of A is ha

If the height of B is twice the corresponding height of A

hb = 3ha

Volume of B Vb = 1/3πr²(3ha)...(2)

If volume of A is 13cm³ and

Va = 1/3πr²ha

Then 13 = 1/3πr²ha

39 = πr²ha

πr² = 39/ha ... (3)

To get Vb, we wil substitute equation 3 into 2 to have;

Vb = 1/3(39/ha)(3ha)

Vb = 39/ha × ha

Vb = 39cm³

Identify the polygon

Answers

Answer: regular hexagon

Step-by-step explanation:

The polygon shown is a regular hexagon.

A regular hexagon is a six-sided polygon with all its sides of equal length and all its interior angles of equal measure. The term "regular" signifies the uniformity and symmetry of this geometric shape. Each side of a regular hexagon is congruent to the others, and each interior angle measures 120 degrees.

Regular hexagons can be found in various contexts, from nature to man-made structures. Honeycombs, for instance, are often composed of hexagonal cells. The six-sided structure allows for efficient packing and maximizes space utilization, which is why it's a prevalent shape in the natural world.

In geometry, a regular hexagon can be divided into equilateral triangles, demonstrating its versatility and ease of partitioning. This feature makes it a fundamental shape in tessellation patterns and various geometric designs.

Additionally, regular hexagons possess rotational symmetry. You can rotate a hexagon by 60 degrees, and it will align perfectly with its original position, making it a key element in tessellation art and certain engineering applications.

Overall, the regular hexagon is an elegant, balanced, and harmonious shape with numerous real-world and mathematical applications, valued for its regularity and aesthetic appeal.

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determine standard from of the equation for the circle with center (h,k)=(-1/50,1/3),r=1/2

Answers

[tex]\bf \textit{equation of a circle}\\\\ (x- h)^2+(y- k)^2= r^2 \qquad center~~(\stackrel{-\frac{1}{50}}{ h},\stackrel{\frac{1}{3}}{ k})\qquad \qquad radius=\stackrel{\frac{1}{2}}{ r} \\\\\\ \left[ x-\left( -\frac{1}{50} \right) \right]^2+\left[ y-\frac{1}{3} \right]^2=\left( \frac{1}{2} \right)^2\implies \left( x+\frac{1}{50} \right)^2+\left( y-\frac{1}{3} \right)^2=\frac{1^2}{2^2} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill \left( x+\frac{1}{50} \right)^2+\left( y-\frac{1}{3} \right)^2=\frac{1}{4}~\hfill[/tex]


The length of the hypotenuse of a right triangle is 145 units. The length of one leg of the triangle is
144 units. Mike wrote the following step to find the length of the unknown leg:

Length of the unknown leg = 1452 − 1442 = 21,025 − 20,736 = 289 units

Which statement best explains whether Mike's step is correct or incorrect?

It is incorrect because the length of the unknown side is the square root of 289.
It is incorrect because the length of the unknown side is the square root of 41,761.
It is correct because the length of the unknown side is the difference of the lengths of the sides.
It is correct because the length of the unknown side is the difference of the squares of the sides.

Answers

D. it is correct because the length of the unknown side is the difference of the squares of the sides.

Answer:

It is correct because the length of the unknown side is the difference of the squares of the sides.

Step-by-step explanation:

Please Assist With This:

Today's Beginning Balance: $42.69

You went shopping with friends today and bought noisy party favors for your Fourth of July party. You wrote a check to Bash Blasts for $9.45. You then went to Dan & Deb's Duds to buy a new shirt for the party, spending $14.35 with your debit card.

*Please Show Work​

Answers

if you want to find out how money you have left then you are supposed to subtract the spent money from the total money.

$42.69-$9.45= $33.24

$33.24- $14.35= $18.89

you have $18.89 of your money left and you have spent $23.80.

Hope this helps

I really need help. Thanks in advance

Answers

Answer:

D

Step-by-step explanation:

9.6 is a floating-point number, therefore, not a integer.

Answer:

d

Step-by-step explanation:

A can company makes a cylindrical can that has a radius of 6 cm and a height of 10 cm. One of the company’s clients needs a cylindrical can that has the same volume but is 15 cm tall. What must the new radius be to meet the client’s need? Round to the nearest tenth of a centimeter.

2.7 cm
4.9 cm
7.3 cm
24.0 cm

Answers

Answer:

  4.9 cm

Step-by-step explanation:

The original can has a volume of ...

  V = πr²h = π(6 cm)²(10 cm) = 360π cm³

The new can will have the same volume, but a different height:

  360π cm³ = πr²(15 cm)

  24 cm² = r² . . . . . divide by 15π cm

  r = √24 cm ≈ 4.9 cm . . . . . take the square root

The new radius must be about 4.9 cm.

Answer:

the anwser is 4.9

Step-by-step explanation:

If R is the set of all integers with absolute value less than 10, A is its subset containing all natural numbers less than 10 and B is the set of all integer solutions of inequality 2x+5<9 that are less than 10 by absolute value (and therefore, it is also a subset of R), draw Venn diagram showing these sets. List elements of sets A, B, their union, and their intersection.

Answers

Answer:

See explanation

Step-by-step explanation:

1. R is the set of all integers with absolute value less than 10, thus

[tex]R=\{a\in \mathbb{Z}\ :\ |a|<10 \}=\\ \\=\{-9,\ -8,\ -7,\ -6,\ -5,\ -4,\ -3,\ -2,\ -1,\ 0,\ 1,\ 2,\ 3,\ 4,\ 5,\ 6,\ 7,\ 8,\ 9\}[/tex]

2. A is its subset containing all natural numbers less than 10, thus

[tex]A\subset R\\ \\A=\{b\in \mathbb{N}\ :\ b<10\}=\{1,\ 2,\ 3,\ 4,\ 5,\ 6,\ 7,\ 8,\ 9\}[/tex]

3. B is the set of all integer solutions of inequality 2x+5<9 that are less than 10 by absolute value (and therefore, it is also a subset of R). First, solve the inequality:

[tex]2x+5<9\\ \\2x<9-5\\ \\2x<4\\ \\x<2[/tex]

Thus,

[tex]B\subset R\\ \\B=\{c\in \mathbb{Z}\ :\ 2c+5<9,\ |c|<10\}=\{c\in \mathbb{Z}\ :\ c<2,\ |c|<10\}=\\ \\=\{-9,\ -8,\ -7,\ -6,\ -5,\ -4,\ -3,\ -2,\ -1,\ 0,\ 1\}[/tex]

See the diagram in attached diagram.

Note that

[tex]A\cup B=R\\ \\A\cap B=\{1\}.[/tex]


If the price of theater tickets increases at 8% per year, about how long will it take to double the price?

Answers

Answer:

[tex]9\ years[/tex]

Step-by-step explanation:

Let

P----> the initial price of the ticket

y ---> the price of the ticket after t years

t---> the time in years

we know that

100%+8%=108%=108/100=1.08

so

[tex]y=P(1.08)^{t}[/tex] ----> equation A

If the price is doubled

then

[tex]y=2P[/tex] -----> equation B

equate equation A and equation B and solve for t

[tex]2P=P(1.08)^{t}[/tex]

Simplify

[tex]2=(1.08)^{t}[/tex]

Apply log both sides

[tex]log(2)=t*log(1.08)[/tex]

[tex]t=log(2)/log(1.08)=9\ years[/tex]

It will take approximately 9 years for the price of theater tickets to double at an annual increase of 8%.

To solve this problem, we can use the Rule of 70, which is a quick and easy way to estimate the number of years required for a quantity to double at a constant growth rate. The Rule of 70 is given by the formula:

[tex]\[ \text{Years to double} \approx \frac{70}{\text{Annual growth rate}} \][/tex]

Given that the annual growth rate is 8%, we can apply this formula:

[tex]\[ \text{Years to double} \approx \frac{70}{8} \] \[ \text{Years to double} \approx 8.75 \][/tex]

Since we cannot have a fraction of a year in this context, we round to the nearest whole number. Therefore, it will take approximately 9 years for the price to double.

A shipping company charges based on calculations of the volume of a rectangular box and the sum of the dimensions of the
box. A square rectangular prism has a side length represented by the linear function f(x), and a height represented by the
linear function g(x).
X
3
4
8
V(x) = (f f-g)(x) S(x) = (f+f+g)(x)
15
2410
35
12
48
Which statement describes the combined functions V(x) and S(x)?
The volume function is linear but the sum function is not
The sum function is linear but the volume function is not
Both the volume function and the sum function are linear
Neither the volume function nor the sum function is linear

Answers

Answer:

B. The sum function is linear but the volume function is not

Step-by-step explanation:

We are given that f(x) and g(x) are linear. Due to this, the sum function S(x) is linear.

And we know the shape of our figure, so we just need to multiply the dimensions for V(x) but the product of three linear functions results in a cubic function, and we conclude V(x) is not linear.

Glad to answer.

Partial qoutients 231÷11

Answers

Answer:

21

Step-by-step explanation:

We are to find partial quotients of 231 ÷ 11

In other words the question asks: How many 11s are there in 231

First, there are twenty 11s in 220 i.e 20 × 11 = 220

Then, subtract 220 from 231 to get 11

Finally ask yourself: How many 11s are in eleven? Definitely its only one 11.

So there are 20 + 1 elevens in 231

Or, there are 21 elevens in 231

Geometry

9. find x (click to see photo)

Answers

8 squared=(x+12)x

8 squared = x squared + 12x

52 = x squared

So x= the square root of 52

Pencils are on sale for $0.99 per dozen. Ms. Klein buys 8 pencils for each of her 96 students. How much will she spend on pencils?

Answers

Answer:

$63.36

Step-by-step explanation:

First we need to determine how many pencils are needed

8 pencils times 96 students

8*96 =768 pencils

A dozen is 12 pencils

Divide the number of pencils needed by 12 to determine how many dozen pencils are needed

768/12 =64

We need 64 dozen pencils

They cost .99 per dozen

64*.99 =63.36

It will cost $63.36 for  the pencils

Select the statement that correctly describes the solution to this system of equations.
5x + 10y = 5
4x + 8y = 5
There is no solution
There is exactly one solution at (5,5)
There are infinitely many solutions
There is exactly one solution at (1,0)

Answers

Answer:

No solution

If you multiply the 1st by 4 and the second by -5

The result is

20x +40y= 20

-20x-40y= -20

When you add both equations the result is  0=0

Step-by-step explanation:

There is no solution for 5x + 10y = 5; 4x + 8y = 5 as they are parallel lines.

What is linear equation?

A linear equation is an algebraic equation of the form y=mx+b. involving only a constant and a first-order (linear) term, where m is the slope and b is the y-intercept.

The given pair of equation is :

5x + 10y = 5

4x + 8y = 5

[tex]a_1[/tex] =5, [tex]b_1[/tex]=10, [tex]c_1[/tex]=5

[tex]a_2[/tex]= 4, [tex]b_2[/tex]= 8, [tex]c_2[/tex]= 5

Now, checking the different condition on two pair of equations

So, we have the satisfied condition as

[tex]\frac{a_1}{a_2} = \frac{b_1}{b_2} \neq \frac{c_1}{c_2}[/tex]

= [tex]\frac{5}{4} =\frac{10}{8}\neq \frac{5}{5}[/tex]

which is condition for parallel.

Thus, There is no solution

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IMAGE ATTACHED PLEASE HELP ME. I NEED TO PASS THIS.

Answers

Answer:

  64

Step-by-step explanation:

From a given point outside the circle, the two tangents to the circle are the same length. This means: JB = JA, CL = AL, and BK = CK.

The perimeter is the sum of all these segments, so is ...

  P = JB +JA +CL +AL +BK +CK = 8 +8 +13 +13 +11 +11

  = 2(8 +13 +11) = 2(32)

  P = 64

The perimeter of the triangle is 64 units.

Cody hiked at an average speed of 1 mile per hour for 5 hours on Saturday. He hiked an average speed of 2 miles per hour for 3 hours on Sunday.
Which explanation correctly tells how to calculate the total number of miles that Cody hiked in two days?

A.Step 1: Multiply 1 × 5.
Step 2: Multiply 2 × 3.
Step 3: Add the two products.

B.Step 1: Multiply 1 × 5.
Step 2: Multiply 2 × 3.
Step 3: Subtract the two products.


C.Step 1: Divide 1 ÷ 5.
Step 2: Divide 2 ÷ 3.
Step 3: Add the two quotients.

D.Step 1: Divide 1 ÷ 5.
Step 2: Divide 2 ÷ 3.
Step 3: Subtract the two quotients.

Answers

Answer:

  A. Step 1: Multiply 1 × 5.

  Step 2: Multiply 2 × 3.

  Step 3: Add the two products.

Step-by-step explanation:

The total number of miles hiked will be the sum of the numbers of miles hiked each day. Each day, the number of miles hiked can be computed by multiplying time by speed:

  distance = speed × time

So, the total number of miles hiked is ...

  total miles = miles on day 1 + miles on day 2 . . . . . (sum, not a difference—eliminates choice B)

  total miles = (speed on day 1)×(time on day 1) + (speed on day 2)×(time on day 2) . . . . . (sum of products—eliminates choices C and D)

Choice A correctly describes the computation.

The equation of the graphed line is 2x – 3y = 12.
What is the x-intercept of the graph?
-4. -3/2. 2/3. 6​

Answers

Hello there! The x-intercept is 6.

The x-intercept is when the y value id equal to zero, and the line crosses the x axis. In this example, you can see that the line passes through x at the value of 6, making that your answer.

I hope this was helpful and have a great rest of your day!

Answer: LAST OPTION.

Step-by-step explanation:

You need to remember that a line intercepts the x-axis when y is equal to zero ([tex]y=0[/tex])

Knowing this and given the graph of the line [tex]2x -3y = 12[/tex], you can observe in the figure attached that this line intercepts the x-axis at this point:

[tex](6,0)[/tex]

Where:

 [tex]x=6[/tex] and  [tex]y=0[/tex]

Therefore, you can identify that the x-intercept is the x-coordinate of this point, which is:

[tex]x=6[/tex]

This matches with the last option.

I need help from question 11- 16! Please help!

Answers

11. Find discriminant.

Answer: D) 0, one real solution

A quadratic function is given of the form:

[tex]ax^2+bx+c=[/tex]

We can find the roots of this equation using the quadratic formula:

[tex]x_{12}=\frac{-b \pm \sqrt{b^2-4ac}}{2a}[/tex]

Where [tex]\Delta=b^2-4ac[/tex] is named the discriminant. This gives us information about the roots without computing them. So, arranging our equation we have:

[tex]4a^2-4a-6=-7 \\ \\ Adding \ 7 \ to \ both \ sides \ of \ the \ equation: \\ \\ 4a^2-4a-6+7=-7+7 \\ \\ 4a^2-4a+1=0 \\ \\ Then \ the \ discriminant: \\ \\ \Delta=(-4)^2-4(4)(1) \\ \\ \Delta=16-16 \\ \\ \boxed{Delta=0}[/tex]

Since the discriminant equals zero, then we just have one real solution.

12. Find discriminant.

Answer: D) -220, no real solution

In this exercise, we have the following equation:

[tex]-r^2-2r+14=-8r^2+6[/tex]

So we need to arrange this equation in the form:

[tex]ax^2+bx+c=[/tex]

Thus:

[tex]-r^2-2r+14=-8r^2+6 \\ \\ Adding \ 8r^2 \ to \ both \ sides \ of \ the \ equation: \\ \\ -r^2-2r+14+8r^2=-8r^2+6+8r^2 \\ \\ Associative \ Property: \\ \\ (-r^2+8r^2)-2r+14=(-8r^2+8r^2)+6 \\ \\ 7r^2-2r+14=6 \\ \\ Subtracting \ 6 \ from \ both \ sides: \\ \\ 7r^2-2r+14-6=6-6 \\ \\ 7r^2-2r+8=0[/tex]

So the discriminant is:

[tex]\Delta=(-2)^2-4(7)(8) \\ \\ \Delta=4-224 \\ \\ \boxed{\Delta=-220}[/tex]

Since the discriminant is less than one, then there is no any real solution

13. Value that completes the squares

Answer: C) 144

What we need to find is the value of [tex]c[/tex] such that:

[tex]x^2+24x+c=0[/tex]

is a perfect square trinomial, that are given of the form:

[tex]a^2x^2\pm 2axb+b^2[/tex]

and can be expressed in squared-binomial form as:

[tex](ax\pm b)^2[/tex]

So we can write our quadratic equation as follows:

[tex]x^2+2(12)x+c \\ \\ So: \\ \\ a=1 \\ \\ b=12 \\ \\ c=b^2 \therefore c=12^2 \therefore \boxed{c=144}[/tex]

Finally, the value of [tex]c[/tex] that completes the square is 144 because:

[tex]x^2+24x+144=(x+12)^2[/tex]

14. Value that completes the square.

Answer: C) [tex]\frac{121}{4}[/tex]

What we need to find is the value of [tex]c[/tex] such that:

[tex]z^2+11z+c=0[/tex]

So we can write our quadratic equation as follows:

[tex]z^2+2\frac{11}{2}z+c \\ \\ So: \\ \\ a=1 \\ \\ b=\frac{11}{2} \\ \\ c=b^2 \therefore c=\left(\frac{11}{2}\left)^2 \therefore \boxed{c=\frac{121}{4}}[/tex]

Finally, the value of [tex]c[/tex] that completes the square is [tex]\frac{121}{4}[/tex] because:

[tex]z^2+11z+\frac{121}{4}=(x+\frac{11}{2})^2[/tex]

15. Rectangle.

In this problem, we need to find the length and width of a rectangle. We are given the area of the rectangle, which is 45 square inches. We know that the formula of the area of a rectangle is:

[tex]A=L\times W[/tex]

From the statement we know that the length of the rectangle is is one inch less than twice the width, this can be written as:

[tex]L=2W-1[/tex]

So we can introduce this into the equation of the area, hence:

[tex]A=L\times W \\ \\ \\ Where: \\ \\ W:Width \\ \\ L:Length[/tex]

[tex]A=(2W-1)(W) \\ \\ But \ A=45: \\ \\ 45=(2W-1)(W) \\ \\ Distributive \ Property:\\ \\ 45=2W^2-W \\ \\ 2W^2-W-45=0 \\ \\ Quadratic \ Formula: \\ \\ x_{12}=\frac{-b\pm \sqrt{b^2-4ac}}{2a} \\ \\ W_{1}=\frac{-(-1)+ \sqrt{(-1)^2-4(2)(-45)}}{2(2)} \\ \\ W_{1}=\frac{1+ \sqrt{1+360}}{4} \therefore W_{1}=5 \\ \\ W_{2}=\frac{-(-1)- \sqrt{(-1)^2-4(2)(-45)}}{2(2)} \\ \\ W_{2}=\frac{1- \sqrt{1+360}}{4} \therefore W_{2}=-\frac{9}{2}[/tex]

The only valid option is [tex]W_{1}[/tex] because is greater than zero. Recall that we can't have a negative value of the width. For the length we have:

[tex]L=2(5)-1 \\ \\ L=9[/tex]

Finally:

[tex]The \ length \ is \ 9 \ inches \\ \\ The \ width \ is \ 5 \ inches[/tex]

16. Satellite

The distance in miles between mars and a satellite is given by the equation:

[tex]d=-9t^2+776[/tex]

where [tex]t[/tex] is the number of hours it has fallen. So we need to find when the satellite will be 452 miles away from mars, that is, [tex]d=452[/tex]:

[tex]d=-9t^2+776 \\ \\ 452=-9t^2+776 \\ \\ 9t^2=776-452 \\ \\ 9t^2=324 \\ \\ t^2=\frac{324}{9} \\ \\ t^2=36 \\ \\ t=\sqrt{36} \\ \\ \boxed{t=6h}[/tex]

Finally, the satellite will be 452 miles away from mars in 6 hours.

Half of a number, x, increase by 7 is greater than -11 and less than-3. What are the possible solutions?

Answers

Answer:

What i got was -1 .

Step-by-step explanation:

A store is having a 20% off sale. If the reduced price of an item is $89.60 what was its original price

please help quickly!

Answers

Answer:

$112

Step-by-step explanation:

Reduced price of $89.60 = 80% (100% - 20%)

You can get the original price (100%) by dividing $89.60 with 80% = $112

The original price is $112.

What is a Percentage?It is a fraction which is divided into 100 parts.Denominator is always 100.It is  useful in many arithmetic calculations.

Given:

A store has 20% off sale.

Reduced price of an item = $89.60

We have to find the original price of an item.

Now, the store has 20% off sale. Hence, the reduced price of an item $89.60 is the 80% of the original price.

Form the given information we can find the original price of an item.

⇒ (80/100) × original price = 89.60

Multiply both sides by 100, we get:

⇒ 80 × original price = 8960

Divide both the sides by 80, we get:

Original Price = $112

Therefore, the original price of an item is $112.

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if a coin is flipped 10 times what is the probability that it will show all heads or all tails?

A. 1/2
B. 1/512
C. 1/1,022
D. 1/1,024
E. 1/2,048

Answers

The answer would be A

If a  coin is flipped 10 times  then the probability that it will show all heads or all tails is 1/512.

What is Probability?

It is a branch of mathematics that deals with the occurrence of a random event.

The probability of getting all heads or all tails on 10 flips in a row is the sum of the probabilities of getting all heads and getting all tails.

P(all heads or all tails) = P(all heads) + P(all tails)

Since the coin flips are independent events, we can use the multiplication rule to find the probability of getting all heads or all tails:

P(all heads) = (1/2)¹⁰ = 1/1024

P(all tails) = (1/2)¹⁰ = 1/1024

So, the probability of getting all heads or all tails is:

P(all heads or all tails) = P(all heads) + P(all tails)

= 1/1024 + 1/1024

= 1/512

Therefore, if a  coin is flipped 10 times  then the probability that it will show all heads or all tails is 1/512.

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according to the line plot what is the total distance run for all of the runners combined​

Answers

Answer:

The answer is 3 8/15 miles.

Hope I helped ; )

Answer:

your answer will be 3 8/15

Step-by-step explanation:

identify the correct way to the nearest 1/8 pound​

Answers

Answer:

2 4/16 = 2 1/4 lb

Step-by-step explanation:

The pointer is 4 of the smallest units above 2. There are 16 of those small units. Each 2 of those units is 1/8 pound, so when the pointer is on a multiple of 2 units, it is on a multiple of 1/8 pound. No guesswork is required to choose the correct weight to the nearest 1/8 pound.

2 4/16 = 2 1/4 lb . . . . the scale reading to the nearest 1/8 pound.

Find the area. The figure is not drawn to scale.

Answers

Area of parallelogram(A) = base×hight

=4.7×3.3=15.51 sq. cm

Answer:

[tex]Area=15.51cm^2[/tex]

Step-by-step explanation:

The given figure is a parallelogram.

The area of a parallelogram is calculated using the formula:

[tex]Area=b\times h[/tex]

The base of the 4.7 cm.

The height is 3.3 cm.

We substitute the given values into the formula to obtain;

[tex]Area=4.7\times 3.3[/tex]

We multiply out to obtain;

[tex]Area=15.51cm^2[/tex]

(3⁵)²/3⁻²

A. 3¹⁰

B. 3¹²

C. [tex]3^{9}[/tex]

D. [tex]3^{8}[/tex]

Answers

Answer:

B. 3¹²

Step-by-step explanation:

To solve this we need to apply the following laws of exponents:

1. [tex](a^n)^m=a^{n*m}[/tex]

2. [tex]a^{-n}=\frac{1}{a^n}[/tex]

Let's apply the first law to the numerator of our fraction and the second law to the denominator. For the numerator, [tex](3^5)^2[/tex], [tex]a=3[/tex], [tex]n=5[/tex], and [tex]m=2[/tex]. For the denominator [tex]3^{-2}[/tex], [tex]a=3[/tex] and [tex]n=-2[/tex]

Replacing values

[tex]\frac{(3^5)^2}{3^{-2}} =\frac{3^{5*2}}{\frac{1}{3^2} } =\frac{3^{10}}{\frac{1}{3^2} }[/tex]

Now, remember that to divide fractions we just need to invert the order of the second fraction and multiply:

[tex]\frac{3^{10}}{\frac{1}{3^2} }=3^{10}*\frac{3^2}{1} =3^{10}*3^2[/tex]

Finally, we can use the law of exponents for multiplication to get our answer:

[tex]a^n*a^m=a^{n+m}[/tex]

[tex]3^{10}*3^2=3^{10+2}=3^{12}[/tex]

We can conclude that the correct answer is B. 3¹²

Starting from the entrance of her school, Alyssa walked 400 feet due north, then 300 feet due east, and ended up at the entrance of a running track. Miki walked directly from the entrance of the school to the entrance of the running track. How many more feet did Alyssa walk than Miki?

Answers

Answer:

Alyssa walked 200 ft more than Miki.

Step-by-step explanation:

According to the Pythagorean theorem formula if we square the a(400) and b(300) and add them both we would get 250,000. From then you square root it to 500. So Miki walked 500ft and Alyssa walked 700ft (400+300). Subtract 500 from 700 and you would get 200ft.

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