初一 数学 暑假作业 因式分解（要步骤) 请详细解答,谢谢! (28 17:38:27)

x^2y^2-x^2-y^2+4xy+1
=x^2y^2+2xy+1-x^2-y^2+2xy
=(xy)^2+2xy+1-(x^2+y^2-2xy)
=(xy+1)^2-(x-y)^2
=(xy+1-x+y)(xy+1+x-y)

注意：x^2表示x的平方，依次类推。

x^2y^2-x^2-y^2+4xy+1
=x^2y^2+2xy+1-(x^2-2xy+y^2)
=(xy+1)^2-(x-y)^2
=(xy+x-y+1)(xy-x+y+1)

原式=x^2y^2+2xy+1-(x^2+y^2-2xy)
=(xy+1)^2-(x-y)^2
=(xy+1+x-y)(xy+1-x+y)

I don't know

自己上网查吧！不会的问爸妈。

x^2y^2+2xy+1)-(x^2-2xy+y^2)
=(xy+1)^2-(x-y)^2
=(xy+1+x-y)(xy+1-x+y)