Let Width = X
So the Length is X +8 ( 8 feet more then the width)
Area of a rectangle is Length x width
Area of pool = 240 square feet
So now we have (x+8) * x = 240
Distribute the left side to get:
x^2 +8x = 240
Subtract 240 from each side:
x^2 + 8x - 240 = 0
Now Factor the polynomial.
(x-12) (x+20) = 0
12-12 = 0
-20 +20 = 0
So x is 12 and -20
since the dimension cannot be a negative number, x = 12
The width = x = 12 feet
The length = the width +8 = 12 +8 = 20 feet
