Answer
15(a+3)(a-3)
Work Step by Step
The factored form of the expression, $
\dfrac{2}{3a+9}
,$ is
\begin{array}{l}\require{cancel}
\dfrac{2}{3(a+3)}
.\end{array}
The factored form of the expression, $
\dfrac{5}{5a-15}
,$ is
\begin{array}{l}\require{cancel}
\dfrac{5}{5(a-3)}
.\end{array}
Hence, the $LCD$ of the given expressions is
\begin{array}{l}\require{cancel}
15(a+3)(a-3)
.\end{array}
