\[\frac{3a}{a - 3} + \frac{a + 5}{6 - 2a} \cdot \frac{54}{5a + a^{2}} =\]
\[= \frac{3a}{a - 3} + \frac{54(a + 5)}{2(3 - a)a(5 + a)} =\]
\[= \frac{3a^{\backslash a}}{a - 3} + \frac{27}{a(3 - a)} = \frac{3a^{2} - 27}{a(a - 3)} =\]
\[= \frac{3\left( a^{2} - 9 \right)}{a(a - 3)} = \frac{3(a - 3)(a + 3)}{a(a - 3)} =\]
\[= \frac{3(a + 3)}{a}.\]