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计算x/(y+z)=y/(x+y+1)=z/(x+y-1)的值

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计算x/(y+z)=y/(x+y+1)=z/(x+y-1)的值
同上.
说得清楚详细些,千万千万不要跳步骤,反正要让我看得懂.
答案上是1/2和-1
好象要分类讨论的,什么当x+y+z=0时,x+y+z≠0时,
计算x/(y+z)=y/(x+y+1)=z/(x+y-1)的值
设x/(y+z)=y/(x+y+1)=z/(x+y-1)=k
则有x=k(y+z)
y=k(x+y+1)
z=k(x+y-1)
三式相加得(x+y+z)=2k(x+y+z)
所以 k=1/2
也就是x/(y+z)=y/(x+y+1)=z/(x+y-1)=k=1/2
我考虑到这一点了,不好意思没写.补充如下:当x+y+z=0时,y+z=-x
x/(y+z)=y/(x+y+1)=z/(x+y-1)=x/(y+z)
=x/(-x)=-1
综上得到x/(y+z)=y/(x+y+1)=z/(x+y-1)=1/2或-1