Với y >= 0 hpt có dạng
\(\left\{{}\begin{matrix}9x-3y=3\\5x+3y=11\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}14x=14\\y=3x-1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=2\end{matrix}\right.\)
Với y < 0 hpt có dạng
\(\left\{{}\begin{matrix}9x+3y=3\\5x+3y=11\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}4x=-8\\y=1-3x\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-2\\y=7\end{matrix}\right.\)