# How do you solve 2x^2 + 18x = 20?

May 16, 2017

$x = - 10$
$x = 1$

#### Explanation:

In order to solve this you must factor it.
1. Subtract the 20 to the left side of the equation.

$2 {x}^{2} + 18 x - 20 = 0$

1. Divide all by 2 in order to isolate the x^2

$\frac{\cancel{2} \left({x}^{2} + 9 x - 10\right)}{\cancel{2}} = \frac{0}{2}$

1. Factor.
You must find 2 numbers that add to 9 and multiply to -10.

Those two factors would $10$ and $- 1$.

add them to $x$ and set to 0

$\left(x + 10\right) \left(x + - 1\right) = 0$

$\textcolor{w h i t e}{0} x + 10 = 0$$\textcolor{w h i t e}{0000}$and$\textcolor{w h i t e}{000}$$x + - 1 = 0$

1. Solve.
$x = - 10$
$x = 1$