# How do you factor completely: 5x^2 + 20x?

Apr 24, 2018

$5 x \left(x + 4\right)$

#### Explanation:

The first thing you should always do whilst factoring is find a common factor. In this case, it would be 5x as it divides into both of these.
Then take each variable and divide it by your factor.
$\frac{5 {x}^{2}}{5 x} = x$

$\frac{20 x}{5 x} = 4$

$5 x$(Your factor) $\left(x + 4\right)$ (The two other variables)
$5 x \left(x + 4\right)$