\[\boxed{\mathbf{1286}\mathbf{.}}\]
\[\left( \frac{9a - 25a^{- 1}}{3a^{\frac{1}{2}} - 5a^{- \frac{1}{2}}} - \frac{a + 7 + 10a^{- 1}}{a^{\frac{1}{2}} + 2a^{- \frac{1}{2}}} \right)^{4} =\]
\[= \left( \frac{2a + 4}{a^{- \frac{1}{2}} \bullet (a + 2)} \right)^{4} =\]
\[= \left( \frac{2a^{\frac{1}{2}} \bullet (a + 2)}{(a + 2)} \right)^{4} = 16a^{2}\]