\(x\left(y+2\right)-y=3\)
\(x\left(y+2\right)=3+y\)
\(x=\frac{3+y}{y+2}\)
\(x=\frac{2+1+y}{y+2}\)
\(x=\frac{y+2}{y+2}+\frac{1}{y+2}\)
\(x=1+\frac{1}{y+2}\)
\(\Rightarrow1⋮y+2\)
\(\Rightarrow y+2\inƯ\left(1\right)=\left\{\pm1\right\}\)
Tự lập bảng
\(x\left(y+2\right)-y=3\)\(\Leftrightarrow x\left(y+2\right)-y-2=3-2\)
\(\Leftrightarrow x\left(y+2\right)-\left(y+2\right)=1\)\(\Leftrightarrow\left(x-1\right)\left(y+2\right)=1\)
Lập bảng giá trị ta có:
| \(x-1\) | \(-1\) | \(1\) |
| \(x\) | \(0\) | \(2\) |
| \(y+2\) | \(-1\) | \(1\) |
| \(y\) | \(-3\) | \(-1\) |
Vậy các cặp giá trị \(\left(x;y\right)\)thoả mãn là: \(\left(0;-3\right)\)hoặc \(\left(2;-1\right)\)
