Find the dimensions of the rectangle if the width is 3 feet less than the length and the area is 40ft^2

Question

jdoe0001 · Answer

|dw:1380924243404:dw|

$\bf 40 = length \times (length - 3)$

solve for "length"

anonymous · Answer

(40) x (-3)?

myininaya · Answer

He is asking you to solve 40=l(l-3) for l

You should recognize this is a quadratic equation.

Try multiply l and (l-3) first 

I replace the length with l.

anonymous · Answer

Thats a one?

myininaya · Answer

A lowercase L. 
1<--this is a one.

myininaya · Answer

40=L(L-3) You like L better?

Either way, this is still a quadratic.
Your objective is 
put into this form 0=ax^2+bx+c .

myininaya · Answer

or since we are using L instead of x
into this form 0=aL^2+bL+c