How do you solve 2x^2-8x=-8?

May 17, 2016

$x = 2$

Explanation:

If
$\textcolor{w h i t e}{\text{XXX}} 2 {x}^{3} - 8 x = - 8$
then
$\textcolor{w h i t e}{\text{XXX}} {x}^{2} - 4 x = - 4$ (after dividing by $2$)

$\textcolor{w h i t e}{\text{XXX}} {x}^{2} - 4 x + 4 = 0$ (after adding $4$ to both sides)

$\textcolor{w h i t e}{\text{XXX}} {\left(x - 2\right)}^{2} = 0$ (factoring)

$\textcolor{w h i t e}{\text{XXX}} \left(x - 2\right) = 0$ (since if $a \cdot b = 0$ then $a = 0$ or $b = 0$)

$\textcolor{w h i t e}{\text{XXX}} x = 2$ (after adding $2$ to both sides)