Question

x^2-x=56

Answer 1

x^2 - x - 56 = 0
x^2 - 8x + 7x - 56 = 0
x(x - 8) + 7(x - 8) = 0
(x + 7)(x - 8) = 0
so either x + 7 = 0 or x - 8 = 0
if x + 7 = 0 ==> x = -7
if x - 8 = 0 ==> x = 8

So solution set is x = -7 and x = 8