\[\left\{ \begin{matrix} 3t + 2z = 5 \\ t - 2z = 15 \\ \end{matrix} \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix} t = 15 + 2z\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ 3(15 + 2z) + 2z = 5 \\ \end{matrix} \right.\ \]
\[45 + 6z + 2z = 5\]
\[8z = - 40\]
\[z = - 5.\]
\[t - 15 + 2z = 15 - 10 = 5.\]
\[Ответ:(5;\ - 5).\]