Упростите выражение (a/(a+4)-a/(a-4))*(a+4)/a.

\[\left( \frac{a^{\backslash a - 4}}{a + 4} - \frac{a^{\backslash a + 4}}{a - 4} \right) \cdot \frac{a + 4}{a} =\]

\[= \frac{a^{2} - 4a - a^{2} - 4a}{(a + 4)(a - 4)} \cdot \frac{a + 4}{a} =\]

\[= \frac{- 8a(a + 4)}{(a + 4)(a - 4) \cdot a} = \frac{- 8}{a - 4} = \frac{8}{4 - a}\]