\[- b^{2} + 2b + 24 = 0\]
\[\left\{ \begin{matrix} b_{1} + b_{2} = \frac{- 2}{- 1} = 2\ \ \ \\ b_{1} \cdot b_{2} = \frac{24}{- 1} = - 24 \\ \end{matrix} \right.\ \]
\[b_{1} = - 4;\ b_{2} = 6:\]
\[\Longrightarrow - b^{2} + 2b + 24 =\]
\[= - (b + 4)(b - 6) =\]
\[= (b + 4)(6 - b).\]