化简方程式 4(x-y)-(x-y)²-4=0
问题描述：
化简方程式 4(x-y)-(x-y)²-4=0
答
4(x-y)-(x-y)²-4=0
(x-y-2)²=0
x-y-2=0
答
4(x-y)-(x-y)²-4=-（(x-y)²+4-4(x-y)）=-(x-y-2)²=0
所以，x-y-2=0
答
4(x-y)-(x-y)²-4=0两边同时乘以-1
(x-y)²-4(x-y)+4=0
（x-y-2）²=0