\[\left\{ \begin{matrix} x + y = 45 \\ x - y = 13 \\ \end{matrix} \right.\ \text{\ \ \ }( + )\]
\[2x = 58\ \ \ \ |\ :2\]
\[x = 29.\]
\[y = 45 - x\]
\[y = 45 - 29\]
\[y = 16.\]
\[Ответ:(29;16).\]