(20+2x)(50+2x) - 20(50) = 456
expand
1000 + 40x + 100x + 4x² - 1000 = 456
combine like terms
4x² + 140x - 456 = 0
divide everything by 4
x² + 35x - 114 = 0
use quadratic equation
x is -38 or 3.
The answer must be positive 9distance cannot be negative)
so the answer is 3ft wide
