\[|a - 5| > 2\]
\[\left\{ \begin{matrix} a - 5 > 2\ \ \ \\ a - 5 < - 2 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\left\{ \begin{matrix} a > 7 \\ a < 3 \\ \end{matrix} \right.\ \ \]
\(Ответ:\ a \in ( - \infty;3) \cup (7; + \infty).\)