因式分解x2＋y2－x2y2－4xy－1；
问题描述：
因式分解x2＋y2－x2y2－4xy－1；
答
x2+y2-x2y2-4xy-1=(x2-2xy+y2)-(x2y2+2xy+1)=(x-y)2-(xy+1)2
答
x2＋y2－x2y2－4xy－1
=x^2-2xy+y^2-(x^2y^2+2xy+1)
=(x-y)^2-(xy+1)^2
=(x-y+xy+1)(x-y-xy-1)
答
x² + y² - x²y² - 4xy - 1= (x² + y² - 2xy) - (x²y² + 2xy + 1)= (x - y)² - (xy + 1)²= (x - y + xy + 1)(x - y - xy - 1)
答
原式＝（x²-2xy+y²）-（x²y²＋2xy+1）
=（x-y)²-(xy＋1)²
=(x-y+xy＋1)(x-y-xy－1)