# How do you solve the equation x^2 - 4x = 4?

May 10, 2015

${x}^{2} - 4 x = 4$

$\implies {x}^{2} - 4 x + 4 = 8$

$a = x$
$b = 2$

${a}^{2} - 2 a b + {b}^{2} = {\left(a - b\right)}^{2}$

${\left(x - 2\right)}^{2} = 8$

$x - 2 = \sqrt{8}$ or $- \sqrt{8}$

${x}_{1} = \sqrt{8} + 2$

${x}_{2} = - \sqrt{8} + 2$