Question

[minh anh]

Cho x/2=y/4=z/5. Tính M= (5x-2y+4z)/(x+3y-5z)

Các bạn giúp mk vs nhé!!!!! Thanks nhiều ạ!!!!!

Answer 1

[Shana]

Đặt \(\frac{x}{2}=\frac{y}{4}=\frac{z}{5}=k\)

\(\Rightarrow x=2k\)

\(y=4k\)

\(z=5k\)

\(\Rightarrow M=\frac{5x-2y+4z}{x+3y-5z}\)

\(=\frac{5\cdot2k-2\cdot4k+4\cdot5k}{2k+3\cdot4k-5\cdot5k}\)

\(=\frac{10k-8k+20k}{2k+12k-25k}\)

\(=\frac{2k\left(5-4+10\right)}{k\left(2+12-25\right)}\)

\(=\frac{2k\cdot11}{k\cdot\left(-11\right)}\)

\(=-2\)