\(\left\{{}\begin{cases}8x-7y=5\\12x+13y=-8\end{cases}}\)
\(\Leftrightarrow\) \(\left\{{}\begin{cases}24x-21y=15\\24x+26y=-16\end{cases}}\)
\(\Leftrightarrow\) \(\left\{{}\begin{cases}-47y=31\\24x+36y=-6\end{cases}}\)
\(\Leftrightarrow\) \(\left\{{}\begin{cases}y=-\dfrac{31}{47}\\x=\dfrac{9}{188}\end{cases}}\)