\[x^{2} - y^{2} = 5\]
\[(x - y)(x + y) = 5\]
\[\left\{ \begin{matrix} x - y = \pm 1 \\ x + y = \pm 5 \\ \end{matrix} \right.\ \ \ \ \ \ или\ \ \]
\[\text{\ \ }\left\{ \begin{matrix} x - y = \pm 5 \\ x + y = \pm 1 \\ \end{matrix} \right.\ \]
\[\left\lbrack \begin{matrix} \left\{ \begin{matrix} x = \pm 3 \\ y = \pm 2 \\ \end{matrix} \right.\ \\ \left\{ \begin{matrix} x = \pm 3 \\ y = \pm 2 \\ \end{matrix} \right.\ \\ \end{matrix} \right.\ \]