\[a^{2}x - 10 = 25x + 2a\]
\[a^{2}x - 25x = 2a + 10\]
\[x\left( a^{2} - 25 \right) = 2 \bullet (a + 5)\]
\[a = 5 \Longrightarrow нет\ решения.\]
\[a = - 5 \Longrightarrow x - любое.\]
\[Ответ:нет\ решения\ при\ a = 5;\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ x - любое\ \ при\ a = - 5;\]
\[\ \ \ \ \ \ \ \ \ \ \ \ x = \frac{2}{a - 5}\ \ \ при\ a \neq \pm 5.\]