1.分解因式：
2.分解因式：9x的平方-6x-y的平方+4y-3_
=(3x-1)^2-(y-2)^2
=(3x+y-3)(3x-y+1）______
3.分解因式：x平方+5xy+x+3y+6y的平方
=(x+2y)(x+3y)+(x+3y)
=(x+3y)(x+2y+1)________________
5.分解因式：x的平方-2X-2y的平方+4y-xy
=(x+y)(x-2y)-2(x+y)
=(x+y)(x-2y-2)___________
6.分解因式：（x-2）的立方-（y-2）的立方-（x-y）的立方
=(x-2-y+2)[(x-2)^2+(x-2)(y-2)+(y-2)^2]-(x-y)^3
=(x-y)[(x-2)^2+(x-2)(y-2)-(x-y)^2]
=(x-y)[(2x-2-y)(y-2)+(x-2)(y-2)]
=(x-y)(y-2)[(2x-2-y+x-2)]
=(x-y)(y-2)(3x-y-4)________
8.分解因式：x(x-1)+y(y+1)-2xy
=x^2-x+y^2+y-2xy
=(x-y)^2-(x-y)
=(x-y)(x-y-1)