Question

The length of a rectangle is 5 centimeters more than the width. The area of the rectangle is 36 centimeters. What is the length?

Answer 1

L= W+5


A= L x W
36= (W+5) x W
36=W²+5W
36-36=W²+5W-36
W²+5W-36= 0
(W-4)(W+9)=0
W-4=0  W+9=0
W=4 W=-9
Since you cannot have a negative width you know that is not correct.

L= 4 + 5
L = 9

Check
A=L x W
36 = 9 x 4
36=36

Answer 2

We can represent the width as x and the length as x+5. Then we can make the area formula A=(x)*(x+5), plug in 36 for A, and solve for x

36=x^2+5x (distribute)
0=x^2+5x-36
0=(x+9)(x-4)
So x=-9 and 4 but dimensions can't be negative so x=4

So if the width is 4, then the length is 9 (4+5)

Hope this helps :)