\(\left\{{}\begin{matrix}\left(a-2\right)3+5b=25\\6a-b=3\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}3a+5b=31\\6a-b=3\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}6a+10b=62\\6a-b=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}11b=59\\6a-b=3\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}a=\frac{46}{33}\\b=\frac{59}{11}\end{matrix}\right.\)