# How do you multiply ( x + 3)^2?

Jul 2, 2015

=color(blue)(x^2 + 6x+ 9

#### Explanation:

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

This expression is of the form of the identity:

${\textcolor{b l u e}{\left(a + b\right)}}^{2} = {a}^{2} + 2 a b + {b}^{2}$

So,
$\textcolor{b l u e}{{\left(x + 3\right)}^{2}} = {x}^{2} + 2 . x . 3 + {3}^{2}$

=color(blue)(x^2 + 6x+ 9