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

May 8, 2015

For the general form of a quadratic
$a {x}^{2} + b x + c = 0$
$x = \frac{- b \pm \sqrt{{b}^{2} - 4 a c}}{2 a}$
$2 {x}^{2} - 5 x - 10 = 0$
x=(-(-5)+-sqrt((-5)^2-4(2)(-10)))/(2(2)
$= \frac{5 \pm \sqrt{105}}{4}$