x^2 = x + 2
x^2 - x - 2 = 0
(x - 2) (x + 1) = 0:
x - 2 = 0 or x + 1 = 0
x = 2 or x + 1 = 0
| x = 2 or x = -1
x^2 = x + 2
x^2 - x - 2 = 0
(x - 2) (x + 1) = 0:
x - 2 = 0 or x + 1 = 0
x = 2 or x + 1 = 0
| x = 2 or x = -1