\(\left\{{}\begin{matrix}\left(x-1\right)\left(y+1\right)=xy-1\\\left(x-3\right)\left(y-3\right)=xy-3\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}xy+x-y-1=xy-1\\xy-3x-3y+9=xy-3\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x-y=0\\-3x-3y=-12\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x-y=0\\x+y=4\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}2x=4\\x=y\end{matrix}\right.\Leftrightarrow x=y=2\)
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