Nate spent $28 on 2 dvds.at this rate how much would 5 dvds cost him

Write an equivalent expression for each of the following. Express your answers in the form a + bi or a - bi

Lana71 [14]

Answer:

44 +14i

Step-by-step explanation:

(5 + i)(9 + i)

FOIL

first 5*9 = 45

inner: 9i

outer :5i

last: i*i = i^2 = -1

Add togheter

45 + 9i+5i -1

Combine like terms

44 +14i

6 0

3 years ago

A football player punts a ball. The path of the ball can be modeled by the equation y = –0.004x2 + x + 2.5, where x is the horiz

Galina-37 [17]

The answer is 252.5 ft

y = –0.004x² + x + 2.5
Let's take y = 0 and we'll get the quadratic equation:

–0.004x² + x + 2.5 = 0
The general formula for quadratic equation is:
ax² + bx + c = 0

a = -0.004
b = 1
c = 2.5

$x_{1,2} = \frac{-b+/- \sqrt{ b^{2}-4ac} }{2a} =\frac{-1+/- \sqrt{ 1^{2}-4*(-0.004)*2.5} }{2*(-0.004)} = \frac{-1+/- \sqrt{1+0.04} }{-0.008} = \\ 
=\frac{-1+/- \sqrt{1.04} }{-0.008} = \frac{-1+/-1.02}{-0.008}$

$x_1=\frac{-1+1.02}{-0.008} = \frac{0.02}{-0.008} = -2.5 \\ 
x_2=\frac{-1-1.02}{-0.008} = \frac{2.02}{-0.008} = 252.5$

Since distance cannot be negative (x1), the correct answer is x2 = 252.5 ft

5 0

3 years ago

Read 2 more answers

What is the nth term rule of the quadratic sequence below? 8,14,22,32 ,44, 58, 74...

DanielleElmas [232]

Answer:

y=n^2+3n+4

Step-by-step explanation:

Sequence,S: 8,14,22,32 ,44, 58, 74...

First differences of S: 6,8,10,12,14,16,...

Second differences of S: 2,2,2,2,2,2,....

It is indeed a quadratic since the 1st differences that are the same are the second differences.

So the 1st term is 8. If the 0th term was listes it would be 4 since 8-4=4 and 6-4=2.

This means our quadratic it is in the form

y=an^2+bn+c where c=4.

So we have y=an^2+bn+4.

Now we can find a and b using two points from our sequence to form a system of equations to solve.

(1,8) gives us 8=a(1)^2+b(1)+4

Simplifying gives 8=a+b+4

Subtracting 4 on both sides gives: 4=a+b

(2,14) gives us 14=a(2)^2+b(2)+4

Simplifying gives 14=4a+2b+4

Subtracting 4 on both sides gives 10=4a+2b

So we have the following system to solve:

4=a+b

10=4a+2b

I'm going to solve using elimination/linear combination style.

Dividing second equation by 2 gives the system as:

4=a+b

5=2a+b

Subtract the 2nd equation from the first gives:

-1=-1a

This implies a=1 since -1=-1(1) is true.

If a+b=4 and a=1, then b=3. Because 3+1=4.

So the equation is y=1n^2+3n+4 or y=n^2+3n+4.

8 0

3 years ago

Chapman’s brickyard sells bricks and blocks. A brick costs $0.38 and a block costs $1.56. The brickyard filled a $24.80 order, w

Lisa [10]

Answer:

number of bricks = 16 and number of blocks = 12

Step-by-step explanation:

From given information it seems , we need to determine number of bricks and number of blocks.

lets assume number of bricks = x

and number of blocks = y

since total items in brickyard is 28

⇒ number of bricks + number of blocks = 28

⇒ x + y = 28 ----------------------- equation 1

Given that cost of 1 brick = $0.38 and cost of 1 block =$1.56

so cost of x bricks = cost of 1 brick × x = 0.38x

And cost of y blocks = cost of 1 block × y = 1.56y

total cost of 28 items order = $24.80

total cost of 28 items = cost of x bricks + cost of y blocks

⇒0.38x + 1.56y = 24.80 ----------------equation 2

Now we are having following two equations

x + y = 28 ----------------------- equation 1

0.38x + 1.56y = 24.80 ----------------equation 2

from equation 1 we get x = 28 - y , substituting this value of x in equation 2 we get

0.38(28 - y) + 1.56y = 24.80

⇒10.64-0.38y+1.56y= 24.80

⇒1.18y = 24.80 - 10.64

⇒y = 14.16÷1.18 = 12

substituting value of y in equation 1 we get

x + 12 = 28

⇒x = 16

hence number of bricks = x = 16 and number of blocks = y = 12

4 0

4 years ago

Raquel can type 63 words every minnute.Rick type then Raquel in 135 minute?Circle the letter of the correct answer.A 1350 B 4599

lozanna [386]

Answer: 1350

Step-by-step explanation:

Here is the correct question.

Raquel can type an average of 63 words per minute. Rick can type 73 words per minute. how many more words can Rick type than Raquel in 135 minutes? Jared chose B as the correct answer. How did he get that answer? Jared said the answer is 4599. How did he get that answer?

Rick's word per minute= 73

Raquel's word per minute= 63

Ricks word in 135minute= 73×135 = 9855

Raquel's word in 135 minutes=63×135 = 8505

=9855 - 8505

= 1350

Rick can type 1350 more words than Raquel in 135 minutes.

Jared's answer is wrong. He got the answer by multiplying 63 by 73 which gives 4599.

8 0

3 years ago

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