Tìm cặp số nguyên x, y sao cho xy - 2x - 2y = 0

* Hướng dẫn giải

$$\begin{gathered} xy-2x-2y=0\iff \left(x-2\right)\left(y-2\right)=4 \\ \left(x;y\right)=\left(3;6\right),\left(6;3\right),\left(1;-2\right),\left(-2;1\right),\left(4;4\right)\left(0;0\right) \end{gathered}$$