-3y+5x-4xy=1 giúp em với ạ

Đáp án:

$-3y + 5x - 4xy = 1$

`⇒ -3y + 5x - 4xy + 15/4 = 19/4`

$⇒ -12y + 20x - 16xy + 15 = 19$

$⇒ (-12y - 16xy) + (20x + 15) = 19$

$⇒ (4x + 3).(-4y + 5) = 19$

$\text{Ta có:}$

$$\begin{array}{|c|c|c|}\hline {4x+3}&\text{1}&\text{19}&\text{-1}&\text{-19}\\\hline {-4x+5}&\text{19}&\text{1}&\text{-19}&\text{-1}\\\hline x&\dfrac{-1}{2}&\text{4}&\text{-1}&\dfrac{-11}{2}\\\hline y&\dfrac{-7}{2}&\text{-1}&\text{-6}&\dfrac{-3}{2}\\\hline &\text{Loại}&\text{t/m}&\text{t/m}&\text{loại}\\\hline \end{array}$$

$\text{Vậy có 2 cặp}$ $x, y$ $t/m$