# How do you factor x^2-x-2=0?

Mar 25, 2016

(x + 1)(x - 2)

#### Explanation:

y = x^2 - x - 2.
Find 2 numbers knowing sum (-1) and product (-2).
They are: 1 and -2.
y = (x + 1)(x - 2)

Shortcut.
Since a - b + c = 0, use shortcut. The 2real roots are (-1) and (-c/a = 2)
Therefor, the 2 factors are:
y = (x + 1)(x - 2)