\(\dfrac{3}{x}=\dfrac{y}{7}\left(đk:x\ne0\right)\)
\(\Leftrightarrow xy=21\)
\(\Rightarrow\left(x,y\right)\inƯ\left(21\right)=\left\{\pm1;\pm3;\pm7;\pm21\right\}\)
Còn lại thì em tự tính tiếp nha
\(\dfrac{3}{x}=\dfrac{y}{7}\Rightarrow xy=21\Rightarrow x;y\inƯ\left(21\right)=\left\{\pm1;\pm3;\pm7;\pm21\right\}\)
x | 1 | -1 | 3 | -3 | 7 | -7 | 21 | -21 |
y | 21 | -21 | 7 | -7 | 3 | -3 | 1 | -1 |