Answer
$8 a^3 + 36 a^2 b + 54 a b^2 + 27 b^3$
Work Step by Step
Using the Binomial Formula, the expression $
(2a+3b)^3
$ expands to
\begin{array}{l}
(2a)^3(3b)^0
\dfrac{3}{1!}(2a)^2(3b)^1+
\dfrac{3\cdot2}{2!}(2a)^1(3b)^2+
\dfrac{3\cdot2\cdot1}{3!}(2a)^0(3b)^3
\\\\=
8 a^3 + 36 a^2 b + 54 a b^2 + 27 b^3
\end{array}
