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

Apr 28, 2018

$y = 4 {\left(x + 3\right)}^{2}$

#### Explanation:

$\text{take out a "color(blue)"common factor } 4$

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

${x}^{2} + 6 x + 9 \text{ is a "color(blue)"perfect square}$

$\text{note that } {\left(a + b\right)}^{2} = {a}^{2} + 2 a b + {b}^{2}$

$\text{with "a=x" and } b = 3$

$\Rightarrow {x}^{2} + 6 x + 9 = {\left(x + 3\right)}^{2}$

$\Rightarrow 4 {x}^{2} + 24 x + 36 = 4 {\left(x + 3\right)}^{2}$