\(xy+x+y=2\)
\(\Rightarrow x\left(y+1\right)+y=2\)
\(\Rightarrow x\left(y+1\right)+y+1=3\)
\(\Rightarrow\left(x+1\right)\left(y+1\right)=3\)
Ta có bảng sau:
| x + 1 | 3 | 1 |
| y + 1 | 1 | 3 |
| x | 2 | 0 |
| y | 0 | 2 |
Vậy cặp số \(\left(x;y\right)\) là \(\left(2;0\right);\left(0;2\right)\)