Question 77647
The width of a rectangle is 7 ft less than the length.  The area of the rectangle is 120 ft2(square).  Find the width of the rectangle.

If we let the length = L

Then, the width, or w, will be L-7

We know that the area of a rectangle is length times width.

So, L(L-7)=120

{{{L^2-7L=120 }}}

{{{L^2-7L-120=0 }}}


(L-15)(L+8) 

So, L=15,-8  length can't be negative, so L=15
So width w=L-7=15-7=8
So width of the rectangle is 8 ft.