\[\left\{ \begin{matrix}
13x - 8y = 28 \\
11x - 8y = 24 \\
\end{matrix} \right.\ \ (–)\]
\[2x = 4\]
\[x = 2.\]
\[8y = 11x - 24\]
\[8y = 22 - 24\]
\[8y = - 2\]
\[y = - \frac{2}{8} = - \frac{1}{4} = - 0,25.\]
\[\left\{ \begin{matrix}
x = 2\ \ \ \ \ \ \ \ \ \\
y = - 0,25 \\
\end{matrix} \right.\ \]
\[Ответ:(2;\ - 0,25).\]