Question

xy-2x-3y=5 tìm xy thuộc z

 

Answer 1

$\begin{array}{c}xy-2x-3y=5\\ \Rightarrow xy-2x-3y+6=5+6\\ \Rightarrow x\left(y-2\right)-3\left(y-2\right)=11\\ \Rightarrow \left(x-3\right)\left(y-2\right)=11\end{array}$

Vì $11=1.11=\left(-1\right).\left(-11\right)$ nên ta có bảng sau:

Vậy $\left(x;y\right)=\left\{\left(-8;1\right);\left(2;-9\right);\left(4;13\right);\left(14;3\right)\right\}$.

Answer 2

Answer 3