\(\left\{{}\begin{matrix}2\left|x-1\right|+\left|x+y\right|=4\\\left|1-x\right|+2\left|x+y\right|=5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}4\left|x-1\right|+2\left|x+y\right|=8\\\left|x-1\right|+2\left|x+y\right|=5\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}3\left|x-1\right|=3\\2\left|x-1\right|+\left|x+y\right|=4\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\left|x-1\right|=1\\\left|x+y\right|=2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x-1\in\left\{1;-1\right\}\\x+y\in\left\{2;-2\right\}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\in\left\{2;0\right\}\\x+y\in\left\{2;-2\right\}\end{matrix}\right.\)
Nếu x+y=2 thì \(\left[{}\begin{matrix}2+y=2\\0+y=2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}y=0\\y=2\end{matrix}\right.\)
Khi x+y=-2 thì \(\left[{}\begin{matrix}2+y=-2\\0+y=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}y=-4\\y=-2\end{matrix}\right.\)
