\(\left(x-1\right)\left(y-2\right)=3\)
\(\Rightarrow\left\{{}\begin{matrix}x-1=1\\y-2=3\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}x-1=3\\y-2=1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}x-1=-3\\y-2=-1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}x-1=-1\\y-2=-3\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=2\\y=5\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}x=4\\y=3\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}x=-2\\y=1\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}x=0\\y=-1\end{matrix}\right.\)
(x - 1) . (y - 2) = 3
=> (x - 1) . (y - 2) = 3 = (-1) . (-3)
= (-3) . (-1) = 1 . 3
=3 . 1
Ta có bảng sau:
| x - 1 | -1 | -3 | 1 | 3 |
| y - 2 | -3 | -1 | 3 | 1 |
| x | 0 | -2 | 2 | 4 |
| y | -1 | 1 | 5 | 3 |
