如果x/2=y/3=z/4,求(2x-y+3z)/(x+y-z)的值

如果x/2=y/3=z/4,求(2x-y+3z)/(x+y-z)的值
如果x/2=y/3=z/4,求(2x-y+3z)/(x+y-z)的值

如果x/2=y/3=z/4,求(2x-y+3z)/(x+y-z)的值
令x/2=y/3=z/4=a, 那么, x=2a; y=3a; z=4a, 代到(2x-y+3z)/(x+y-z)里面,就等于（4a-3a+12a)/(2a+3a-4a);
就等于13a/a = 13