How do you solve the quadratic x^2-2x-8=0 using any method?

Sep 8, 2016

$x \in \left\{- 2 , 4\right\}$

Explanation:

${x}^{2} - 2 x - 8 = 0$ can be factored as
$\textcolor{w h i t e}{\text{XXX}} \left(x + 2\right) \left(x - 4\right) = 0$
which implies
either
$\textcolor{w h i t e}{\text{XXX")x+2=0color(white)("XX")rarrcolor(white)("XX}} x = - 2$
or
$\textcolor{w h i t e}{\text{XXX")x-4=0color(white)("XX")rarrcolor(white)("XX}} x = 4$