因:x+y=x/yxy+y2=x又:xy=x+yx+y+y2=xy2=-y因:y2一定为负数,所以-y为正数,即y为负数又:x+y=x/y=xyx=xy2y2=1所以:y=-1所以代入:x+y=x/y得x-1=x/-12x=1x=1/2