x(y+2)=-8.Tìm x thuộc Z

Đáp án: `(x, y) in {(1;-10),(-1;6),(2;-6),(-2; 2),(4;-4),(-4;0),(8;-3),(-8;-1)`

Giải thích các bước giải:

Ta có: `x(y+2)=-8`

`=> x` và `(y+2) in Ư (-8)={+-1; +-2; +-4; +-8}`

Ta có bảng sau:

$$\begin{array}{|c|c|c|}\hline \text{x}&\text{1}&\text{-1}&\text{2}&\text{-2}&\text{4}&\text{-4}&\text{8}&\text{-8}\\\hline \text{y+2}&\text{-8}&\text{8}&\text{-4}&\text{4}&\text{-2}&\text{2}&\text{-1}&\text{1}\\\hline \text{y}&\text{-10}&\text{6}&\text{-6}&\text{2}&\text{-4}&\text{0}&\text{-3}&\text{-1}\\\hline\end{array}$$

Vậy`,`

`(x, y) in {(1;-10),(-1;6),(2;-6),(-2; 2),(4;-4),(-4;0),(8;-3),(-8;-1)`