Question

The width of a rectangle is 8 units less than the length. The area of the rectangle is 9 units. What is the length, in units, of the rectangle?

Answer 1

w=l-8
a=9
a=lw
9=(l-8)l
9=l²-8l
0=l²-8l-9
factor
0=(l-9)(l+1)
set to zero
l-9=0
l=9
l+1=0
l=-1, false length can't be negative


l=9
the length is 9 units long