# How do you solve x^2 - 3x - 88 = 0 by completing the square?

May 6, 2016

x = -8 and x = 11

#### Explanation:

${x}^{2} - 3 x = 88$
${x}^{2} - \left(\frac{3}{2}\right) x + \frac{9}{4} = 88 + \frac{9}{4}$
${\left(x - \frac{3}{2}\right)}^{\circ} = \frac{361}{4}$
Calculator gives -->
$\left(x - \frac{3}{2}\right) = \pm \frac{19}{2}$
$x = \frac{3}{2} \pm \frac{19}{2} = \frac{3 \pm 19}{2}$
x = 11 and x = -8