Question

The width w of a rectangular swimming pool is 7x^2. The area A of the pool is 7x^3 – 42x^2. What is an expression for the length of the pool? This is what I have done so far.
W=7x^2
7x^3-42x^2=7x^2(x-6)

Answer 1

@AccessDenied @beccaboo333 @whpalmer4 Help!!!

Answer 2

\[A = lw\]right?

Answer 3

Yes..

Answer 4

I don't know what to do next after that equation part..Like solving it.

Answer 5

if you know how to do polynomial division, you could find
\[l = \frac{A}{w}\]

or if you've factored \(A\) and one of the factors is \(W\), then the other factor must be \(l\)

Answer 6

I have no clue how to do that.

Answer 7

Okay, well you started to factor A, completed it, even.

\[A = 7x^2(x-6)\]If \(A = l*w\) and \(w = 7x^2\), doesn't that mean \[A = w(x-6)\]?

Answer 8

Yes...I guess..idk..

Answer 9

Would it be \[7x^2(x-6) l* 7x^2\]

Answer 10

It does :-)

\[A = 7x^3 – 42x^2= 7x^2(x-6)\]
\[A = l*w\]\[w = 7x^2\]
\[A = 7x^2*l\]\[7x^2(x-6) = 7x^2*l\]\[\frac{7x^2(x-6)}{7x^2} = \frac{7x^2*l}{7x^2}\]\[\frac{\cancel{7x^2}(x-6)}{\cancel{7x^2}} = \frac{\cancel{7x^2}*l}{\cancel{7x^2}}\] \[l=(x-6)\]

Answer 11

Ok. I see what you did! Makes sense now:) Thank you so much!!!!!

Answer 12

You're welcome!

Answer 13

It seems so obvious to me, I want it to be that way for you, too :-)

Answer 14

Yea..Like I need it step by step...At least somebody helped me solve this!