\[\left\{ \begin{matrix} 5a - 3b = 14 \\ 2a + b = 10\ \ \ \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} 5a - 3 \cdot (10 - 2a) = 14 \\ b = 10 - 2a\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} 5a - 30 + 6a = 14 \\ b = 10 - 2a\ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \]
\[\left\{ \begin{matrix} 11a = 44\ \ \ \ \ \ \\ b = 10 - 2a \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} a = 4 \\ b = 2 \\ \end{matrix} \right.\ \]
\[Ответ:(4;2).\]