x2-y2-2x-2y化简2在x后面的是平方老师的答案为什么是0
问题描述:
x2-y2-2x-2y化简
2在x后面的是平方
老师的答案为什么是0
答
(x-1)2-(y+1)2
2是平方
答
x2-y2-2x-2y
=(x+y)(x-y)-2(x+y)
=(x+y)(x-y-2)
答
x²-y²-2x-2y
=(x+y)(x-y)-2(x+y)
=(x+y)(x-y-2)