Question

If the area of a rectangle is given by 12x^2 + 28x + 8 and the length is 2x + 4, find the width.

6x + 5

6x - 5

6x + 2

6x - 2

Answer 1

@rvc

Answer 2

@Marissalk19

Answer 3

@ganeshie8

Answer 4

What is the formula for the area of a rectangle?

Answer 5

a=wl

Answer 6

If you know a and you know l, how do you find w?

Answer 7

divide

Answer 8

That's right. so if

\[ \large A= 12x^2 + 28x + 8 \]

and

\[ \lerge l = 2x +4 \]

Just divide to find the width.

Do you know how to divide polynomials?

Answer 9

nope

Answer 10

12x^2/ 2x?

Answer 11

which would be 6

Answer 12

Okay. You want to divide:

\[ \large 12x^2 + 28x + 8 \]

by

\[\large 2x + 4 \]

This is very similar to long division. How many times will \(2x\) go into \(12x^2\)?

Answer 13

6

Answer 14

t goes more than that. it is twice x into 12 x squared.

Answer 15

ok

Answer 16

i got 6x

Answer 17

2x goes into \(12x^2\)?

6 takes care of the constant, but what about x?

Answer 18

Okay good.

Answer 19

well it woul be 12 times 12

Answer 20

would

Answer 21

144/2=72

Answer 22

now 6x times 2x + 4 = \(12x^2 + 24x\), so subtract that from the area equation.

\[ \large 12x^2 + 28x + 8 - (12x^2 +\24x) \] ?

Answer 23

2x+2

Answer 24

\large 12x^2 + 28x + 8 - (12x^2 +24x) = 4x + 8\]
And 2x+4 obviously goes into that 2 times.

so the width is 6x + 2

Answer 25

i mean 6x

Answer 26

+2

Answer 27

If you do not need any more help with this question you should close it.