Tìm số nguyên x, y biết: 2xy-x+y=6

Đáp án:

Giải thích các bước giải:

`2xy - x + y = 6`

`=> x(2y - 1) + y = 6`

`=> 2 . [ x(2y - 1) + y ] = 2 . 6`

`=> 2x(2y - 1) + 2y = 12`

`=> 2x(2y - 1) + 2y - 1 = 12 - 1`

`=> (2x + 1)(2y - 1) = 11`

Ta có bảng :

\begin{array}{|c|c|c|}\hline \text{2x + 1}&\text{1}&\text{-1}&\text{11}&\text{-11}\\\hline \text{2y - 1}&\text{11}&\text{-11}&\text{1}&\text{-1}\\\hline \text{x}&\text{0}&\text{-1}&\text{5}&\text{-6}\\\hline \text{y}&\text{6}&\text{-5}&\text{1}&\text{0}\\\hline \text{C/L}&\text{C}&\text{C}&\text{C}&\text{C}\\\hline\end{array}

Vậy `(x; y) = (0; 6), (-1; -5), (5; 1), (-6; 0)`