# How do you solve the quadratic equation by completing the square: X^2 + 3x – 1 = 0?

Jul 18, 2015

Solve y = x^2 + 3x - 1 = 0
$x = - \frac{3}{2} \pm \frac{\sqrt{13}}{2}$

#### Explanation:

${x}^{2} + 3 x + \frac{9}{4} = 1 + \frac{9}{4} = \frac{13}{4}$
${\left(x + \frac{3}{2}\right)}^{2} = \frac{13}{4}$
$\left(x + \frac{3}{2}\right) = \pm \frac{\sqrt{13}}{2}$

$x = - \frac{3}{2} \pm \frac{\sqrt{13}}{2}$