\[16y^{2} + y^{2} = 17\]
\[17y^{2} = 17\]
\[y^{2} = 1\]
\[y = \pm 1.\]
\[\left\{ \begin{matrix} y = 1\ \ \ \ \\ x = - 4 \\ \end{matrix} \right.\ \ \ \ или\ \ \ \left\{ \begin{matrix} y = - 1 \\ x = 4\ \ \ \\ \end{matrix} \right.\ \]
\[Ответ:( - 4;1);\ \ (4; - 1).\]