Question

cho  \(\dfrac{x}{3}=\dfrac{y}{4}\)và \(\dfrac{y}{5}\)=\(\dfrac{z}{6}\)Tính M= \(\dfrac{2x+3y+4z}{3x+4y+5z}\)

Answer 1

\(\dfrac{x}{3}=\dfrac{y}{4};\dfrac{y}{5}=\dfrac{z}{6}\Rightarrow\dfrac{x}{15}=\dfrac{y}{20}=\dfrac{z}{24}\)

Đặt \(\dfrac{x}{15}=\dfrac{y}{20}=\dfrac{z}{24}=k\Rightarrow x=15k;y=20k;z=24k\)

\(M=\dfrac{30k+60k+96k}{45k+80k+120k}=\dfrac{186}{245}\)