已知x=y/3=z/5,xyz≠0,求(x-3y+5z)/(x+3y-5z)的值

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已知x=y/3=z/5,xyz≠0,求(x-3y+5z)/(x+3y-5z)的值
已知x=y/3=z/5,xyz≠0,求(x-3y+5z)/(x+3y-5z)的值

已知x=y/3=z/5,xyz≠0,求(x-3y+5z)/(x+3y-5z)的值
由x=y/3=z/5,得x:y:z=1:3:5
设x=a,y=3a,z=5a
(x-3y+5z)/(x+3y-5z)
=(a-9a+25a)/(a+9a-25a)
=-17/15

因为 X=y/3=z/5
所以y=3x z=5x
所以3y=9x 5z=25x
则(x-3y+5z)/(x+3y-5z)=(x-9x+25z)/(x+9z-25x)=-17/15

不知道对不对 不过方法肯定是对的

由x=y/3=z/5,得y=3x,z=5x
(x-3y+5z)/(x+3y-5z)
=(x-9x+25x)/(x+9x-25x)
=17x/(-15x)
=-17/15