因式分解:1.(x-3y)^2-4x^2 2.x^2+2xy+y^2-2x-2y+1

问题描述:

因式分解:1.(x-3y)^2-4x^2 2.x^2+2xy+y^2-2x-2y+1

1.(x-3y)^2-4x^2
=(x-3y+2x)(x-3y-2x)
=3(x-y)(-3y-x)
=3(y-x)(3y+x)
2.x^2+2xy+y^2-2x-2y+1
=(x+y)^2-2(x+y)+1
=(x+y-1)^2