# How do you solve x^2 - 8x - 20 = 0?

Feb 17, 2016

x = 10 , x = - 2

#### Explanation:

first factor the quadratic by considering the factors of - 20 which sum to - 8.
These are - 10 and +2

$\Rightarrow {x}^{2} - 8 x - 20 = \left(x - 10\right) \left(x + 2\right) = 0$

hence (x - 10 ) = 0 $\Rightarrow x = 10 \text{ or } \left(x + 2\right) = 0 \Rightarrow x = - 2$