# How do you solve the equation 2x^2=x+15 by graphing?

Jan 17, 2017

(-2.5, 0); (3, 0)

#### Explanation:

Given -

$2 {x}^{2} = x + 15$

Have it as -

$- 2 {x}^{2} + x + 15 = 0$
$y = - 2 {x}^{2} + x + 15$

Its vertex is

$x = \frac{- b}{2 a} = \frac{- 1}{2 \times \left(- 2\right)} = \frac{1}{4} = 0.25$

After finding the vertex take a few points on either side of it.
Calculate their corresponding $y$ values.
Plot them on a graph.
Take the coordinates where the curve cuts the x-axis.