Not much of an explanation in your answers, ILP
x = number x^2 = square of number
x^2 + x = 240
x^2 + x - 240 = 0
Use Quadratic formula with a = 1 b=1 c = -240
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
and you will find x = -16 or +15 (throw out...not even)
Check : ( -16)^2 + -16 = 240 Check !
