Từ 5x=4y \(\rightarrow\)x/4=y/5 \(\Rightarrow\)x/4=y/5=2y-x/2.5-4=3/6=1/2 \(\Rightarrow\)x/4=1/2\(\rightarrow\)x=2 \(\Rightarrow\)y/5=1/2\(\rightarrow\)y=2,5
5x=4y ➝\(\dfrac{x}{4}=\dfrac{y}{5}\)
Đặt \(\dfrac{x}{4}=\dfrac{y}{5}=K\)
Ta có : \(x=4.K\) ; \(y=5.K\)
2\(y-x=3\)
=\(2.5.K-4.K=3\)
=\(10.K-4.K=3\)
\(6.K=3\)
➝k=0.5
\(\dfrac{x}{4}=0.5\xrightarrow[]{}x=10\)
\(\dfrac{y}{5}=0.5\xrightarrow[]{}y=7.5\)