# How do you factor 4x^2 + 24x + 36?

Mar 8, 2018

$4 \left(x + 3\right) \left(x + 3\right)$

#### Explanation:

First, factor out four from each of the elements:

$4 \left({x}^{2} + 6 x + 9\right)$

Then find factors of the last and first elements that when added make the middle one:

$3 \times 3 = 9 \text{ }$ and $\text{ } 3 + 3 = 6$

$\implies 4 \left({x}^{2} + 3 x + 3 x + 9\right)$

$\implies 4 \left(x \left(x + 3\right) + 3 \left(x + 3\right)\right)$

$\implies 4 \left(x + 3\right) \left(x + 3\right)$