# How do you factor the expression 9x^2 - 16?

Mar 20, 2018

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

#### Explanation:

$9 {x}^{2} - 16$

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

The identity for ${a}^{2} - {b}^{2}$ is equal to

$\left(a + b\right) \left(a - b\right)$.

Here , $a = 3 x$ and $b = 4$.

So , we get ${\left(3 x\right)}^{2} - {\left(4\right)}^{2}$

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