Đáp án `+` Giải thích các bước giải:

`(x+4) (y-5) = 2`

Ta có:

`2= 1 . 2 = (-1). (-2) = 2 . 1 = (-2) . (-1)`

Ta có bảng:

\begin{array}{|c|c|c|}\hline \text{x + 4}&\text{y-5}&\text{x}&\text{y}\\\hline \text{1}&\text{2}&\text{-3}&\text{7}\\\hline \text{2}&\text{1}&\text{-2}&\text{6}\\\hline \text{-1}&\text{-2}&\text{-5}&\text{3}\\\hline \text{-2}&\text{-1}&\text{-6}&\text{4}\\\hline\end{array}

Vậy `(x,y) \in {(−3; 7), (−2; 6), (−5; 3), (−6; 4)}`