\[\left( a^{3} - 16a \right) \cdot \left( \frac{1^{\backslash a - 4}}{a + 4} - \frac{1^{\backslash a + 4}}{a - 4} \right) =\]
\[= \left( a^{3} - 16a \right) \cdot \frac{a - 4 - a - 4}{(a - 4)(a + 4)} =\]
\[= \frac{- 8a\left( a^{2} - 16 \right)}{a^{2} - 16} = - 8a;\]
\[a = - 45:\]
\[- 8a = - 8 \cdot ( - 45) = 360.\]