一道数学题:若x:y:z=2:3:4,求分式x-y-z /2x+3y的值

问题描述:

一道数学题:若x:y:z=2:3:4,求分式x-y-z /2x+3y的值
若x:y:z=2:3:4,求分式x-y-z /2x+3y的值

令x=2a,y=3a,z=4a,
于是x-y-z /2x+3y = (-5a)/(13a) = -5/13