Suy ra \(\left\{{}\begin{matrix}y+1=3\\xy-1=1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y+1=-3\\xy-1=-1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y+1=-1\\xy-1=-3\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y+1=1\\xy-1=3\end{matrix}\right.\)
Suy ra \(\left\{{}\begin{matrix}y=2\\2x-1=1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y=-4\\-4x-1=-1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y=-2\\-2x-1=-3\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y=0\\x\cdot0-1=3\end{matrix}\right.\) (loại)
Suy ra \(\left\{{}\begin{matrix}y=2\\x=1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y=-4\\x=0\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}y=-2\\x=1\end{matrix}\right.\)
