# How do you solve 2x^2 - 5x – 10 = 0  using the quadratic formula?

May 11, 2016

$\frac{5 \pm \sqrt{105}}{4}$
$y = 2 {x}^{2} - 5 x - 10 = 0$
$D = {d}^{2} = {b}^{2} - 4 a c = 25 + 80 = 105$ --> $d = \pm \sqrt{105}$
$x = - \frac{b}{2 a} \pm \frac{d}{2 a} = \frac{5}{4} \pm \frac{\sqrt{105}}{4} = \frac{5 \pm \sqrt{105}}{4}$