\[a^{2}x - 2a = 4 \bullet (x - 1)\]
\[a^{2}x - 2a = 4x - 4\]
\[a^{2}x - 4x = 2a - 4\]
\[x\left( a^{2} - 4 \right) = 2 \bullet (a - 2)\]
\[x(a - 2)(a + 2) = 2 \bullet (a - 2)\]
\[a = - 2 \Longrightarrow нет\ решения.\]
\[a = 2 \Longrightarrow x - любое.\]
\[Ответ:нет\ решения\ при\ \]
\[a = - 2;\ \ \]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ x - любое\ при\ a = 2;\]
\[\ \ \ \ \ \ \ \ \ \ \ x = \frac{2}{a + 2}\ при\ a \neq \pm 2.\]