\(\left\{{}\begin{matrix}2y-3x=7\\y+4x=9\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}8y-12x=28\\3y+12x=27\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}11y=55\\y+4x=9\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}y=5\\5+4x=9\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}y=5\\x=1\end{matrix}\right.\)
Vậy nghiệm hpt: \(\left(x;y\right)=\left(1;5\right)\)