\[b^{\backslash b^{2} - 25} - \ \frac{b^{3} - 24b - 5}{b^{2} - 25} =\]
\[= \frac{b^{3} - 25b - b^{3} + 24b + 5}{b^{2} - 25} =\]
\[= \frac{- b + 5}{(b - 5)(b + 5)} =\]
\[= \frac{- (b - 5)}{(b - 5)(b + 5)} = - \frac{1}{b + 5}\]
\[b = - 5,5:\]
\[- \frac{1}{b + 5} = - \frac{1}{- 5,5 + 5} =\]
\[= - \frac{1}{- 0,5} = 2.\]