posted by joshua .
The area of a rectangular field is x^2-x-72 m^2. The length of the field is x+8 m. What is the width of the field in meters?
divide x^2 - x - 72 by x+8
(x+8)(x - ?) = x^2 - x - 72
looks like the missing bracket must be (x-9)
the width is x-9
check by multiplying it back out