(x - 12)( x + 11)= 0
Therefore x = 12 or x = - 11 (reject since x cannot be negative)
Substitute x = 12 into the 4 sides given:
x + 2 = 12 + 2 = 14
2x + 1 = 2(12) + 1 = 25
x - 5 = 12 - 5 = 7
x^2 - 3x = (12)^2 - 3(12) = 108
Hence, the 4 sides of the quadrilateral are 14 inches, 25 inches , 7 inches and 108 inches.