若x:y:z=3:2:1,则x+2y-z/2x-y+z=

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若x:y:z=3:2:1,则x+2y-z/2x-y+z=

若x:y:z=3:2:1,则x+2y-z/2x-y+z=
若x:y:z=3:2:1,则x+2y-z/2x-y+z=

若x:y:z=3:2:1,则x+2y-z/2x-y+z=
依题意可设x=3t,y=2t,z=t,
∴(x+2y-z)/(2x-y+z)
=(3t+4t-t)/(6t-2t+t)
=6/5.

教你个小窍门,这种题如果是填空题,就可以根据题目直接设x=3,y=2,z=1,那么原题=(3+4-1)/(6-2+1)=6/5

x:y:z=3:2:1
直接代入
x+2y-z/2x-y+z=(3+2*2-1)/(2*3-2+1)=6/5
【或
x:y:z=3:2:1=3m:2m:m
x=3m,y=2m,z=m
x+2y-z/2x-y+z=(3+2*2-1)/(2*3-2+1)=6/5