已知x/1=y/3=z/5(x不等于0),求(x+3y-z)/(x-3y+2z)的值.

问题描述:

已知x/1=y/3=z/5(x不等于0),求(x+3y-z)/(x-3y+2z)的值.

设x=a,则y=3a,z=5a,
(x+3y-z)/(x-3y+2z)
=(a+3*3a-5a)/(a-3*3a+2*5a)
=5a/2a
=5/2