\(4x=3y\Rightarrow\dfrac{x}{3}=\dfrac{y}{4}\)
Áp dụng t/c dãy tỉ số bằng nhau:
\(\dfrac{x}{3}=\dfrac{y}{4}=\dfrac{2x}{6}=\dfrac{3y}{12}=\dfrac{2x-3y}{6-12}=\dfrac{6}{-6}=-1\)
\(\Rightarrow\left\{{}\begin{matrix}x=3.\left(-1\right)=-3\\y=4.\left(-1\right)=-4\end{matrix}\right.\)