x2+y2-x2y2-4xy-1

分类: 作业答案 • 2022-07-16 16:25:24

问题描述：

x2+y2-x2y2-4xy-1

答

x²+y²-x²y²-4xy-1
=(x²-2xy+y²)-(x²y²+2xy+1)
=(x+y)²-(xy+1)²
=[(x+y)+(xy+1)][(x+y)-(xy+1)]
=(x+y+xy+1)(x+y-xy-1)