因为x=y,所以2x=2y,所以2s-(x+y)=2y-(x+y),即x-y=y-x则(x-y)/(y-x)/(x-y)对不对
问题描述：
因为x=y,所以2x=2y,所以2s-(x+y)=2y-(x+y),即x-y=y-x则(x-y)/(y-x)/(x-y)对不对
答
不对,
x-y=0.
分母不能为0,(x-y)/(y-x)没有意义哪一步错了？？