Giải:
\(\dfrac{x}{y}=\dfrac{11}{3}\Rightarrow\dfrac{x}{11}=\dfrac{y}{3}\)
Đặt \(\dfrac{x}{11}=\dfrac{y}{3}=k\) \(\Rightarrow x=11k;y=3k\)
Thay \(x=11k;y=3k\) vào \(M\) ta có:
\(M=\dfrac{3x-5y}{2x-y}=\dfrac{3.11k-5.3k}{2.11k-3k}\)
\(=\dfrac{33k-15k}{22k-3k}=\dfrac{\left(33-15\right)k}{\left(22-3\right)k}\)
\(=\dfrac{18k}{19k}=\dfrac{18}{19}\)
Vậy \(M=\dfrac{18}{19}\)
Bài giải
Vì \(\dfrac{x}{y}=\dfrac{11}{3}\Rightarrow\dfrac{x}{11}=\dfrac{y}{3}\)
Đặt \(\dfrac{x}{11}=\dfrac{y}{3}=k\Rightarrow x=11k;y=3k\)
Ta có : M = \(\dfrac{3x-5y}{2x-y}=\dfrac{3.11k-5.3k}{2.11k-3k}=\dfrac{33k-15k}{22k-3k}=\dfrac{\left(33-15\right).k}{\left(22-3\right).k}=\dfrac{18k}{19k}=\dfrac{18}{19}.\)Vậy \(M=\dfrac{18}{19}\)
