# How do you solve using the completing the square method x^2 + 6x - 66 = 6?

May 20, 2016

6 and -12

#### Explanation:

${x}^{2} + 6 x = 72$
${x}^{2} + 6 x + 9 = 72 + 9 = 81$
${\left(x + 3\right)}^{2} = 81$
$\left(x + 3\right) = \pm 9$
$x = - 3 - 9 = - 12$
$x = - 3 + 9 = 6$