\[ax + 2 = 2a + x\]
\[ax - x = 2a - 2\]
\[x(a - 1) = 2 \bullet (a - 1)\]
\[a = 1 \Longrightarrow x - любое.\]
\[Ответ:a \in ( - \infty;1) \cup (1;\ + \infty).\]