Answer
$81+216a+216a^2+96a^3+16a^4$
Work Step by Step
Using the Binomial Formula, the expression $
(3+2a)^4
$ expands to
\begin{array}{l}
3^4(2a)0+
\dfrac{4}{1!}3^3(2a)1+
\dfrac{4\cdot3}{2!}3^2(2a)2+
\dfrac{4\cdot3\cdot2}{3!}3^1(2a)3+
\dfrac{4\cdot3\cdot2\cdot1}{4!}3^0(2a)4
\\\\=
81+216a+216a^2+96a^3+16a^4
\end{array}
