如果x/2=y/7=z/5,且x*y*z不等于零,则(x+y+z)/(3x-y)=______.
问题描述:
如果x/2=y/7=z/5,且x*y*z不等于零,则(x+y+z)/(3x-y)=______.
答
令x/2=y/7=z/5=k
则x=2k,y=7k,z=5k
(x+y+z)/(3x-y)
=(2k+7k+5k)/(6k-7k)
=-14