320 + 16x = x^2

Answer 1

I will assume we are solving

x^2 - 16x - 320 = 0

how about completing the square
x^2 - 16x + .. = 320 + ...
x^2 - 16x + 64 = 320+64
(x-8)^2 = 384
x-8 = ±√384 = 8√6
x = 8 ± 8√6