1.分解因式：a平方+b平方+4a+2b+3=________2.分解因式：9x的平方-6x-y的平方+4y-3_______3.分解因式：x平方+5xy+x+3y+6y的平方________4.分解因式：ab（a+b）的平方-（a+b）的平方+1__________5.分解因式：x的平方-2X-2y的平方+4y-xy___________6.分解因式：（x-2）的立方-（y-2）的立方-（x-y）的立方=___________7.在实数范围内分解因式：x的4次方+x的立方-3x的平方-4x-a=________________8.分解因式：x(x-1)+y(y+1)-2xy=__9.分解因式：x的立方+5x的平方+3x-9

1. a^2-b^2+4a+2b+3 9.x^3+5x^2+3x-9
=(a^2+4a+4)-(b^2-2b+1) =x^2(x+3)+2x^2+3x-9
=(a+2)^2-(b-1)^2 =x^2(x+3)+(2x-3)(x+3)
=[(a+2)+(b-1)][(a+2)-(b-1)] =(x+3)(x^2+2x-3)
=(a+b+1)(a-b+3) = (x+3)(x-1)(x+3)
=(x+3)^2(x-1)
2. 9x^2-6x-y^2+4y-3
=(9X^2-6X+1)-(Y^2-4Y+4)
=(3X-1)^2-(Y-2)^2
=(3X-1+Y-2)(3X-1-Y+2)
=(3X+Y-3)(3X-Y+1)
3.x^2+5xy+x+3y+6y^2
=X^2+5XY+6Y^2+X+3Y
=（X+2Y)(X+3Y)+X+3Y
=(X+3Y）（X+2Y+1）
4.ab(a+b)^2-(a+b)^2+1
==a(a+b)*b(a+b)-(a+b)(a+b)+1
=a(a+b)*b(a+b)-a(a+b)-b(a+b)+1
=[a(a+b)-1][b(a+b)-1]
5.x^2-2x-2y^2+4y-xy
=(x^2-xy-2y^2)-(2x-4y)
=(x-2y)(x+y)-2(x-2y)
=(x-2y)(x+y-2)
6.〔x-2)^3-〔y-2)^3-〔x-y)*^3
=(x-2)^3+[(2-y)-(x-y)]*[(2-y)^2+(2-y)*(x-y)+(x-y)^2]
=(x-2)^3+(-x+2)*[(2-y)^2+(2-y)*(x-y)+(x-y)^2]
=(x-2){(x-2)^2-[(4-4y+y^2)+(2x-2y-xy+y^2)+(x^2-2xy+y^2)]
=(x-2)(x^2-4x+4-4+4y-y^2-2x+2y+xy-y^2-x^2+2xy-y^2)
=(x-2)(-6x+6y+3xy-3y^2)
=3(x-2)[-2(x-y)+y(x-y)]
=3(x-2)(y-2)(x-y)
7.x^4+x^3-3x^2-4x-4
=(x^4+x^3+x^2)-4x^2-4x-4
=x^2(x^2+x+1)-4(x^2+x+1)
=(x^2+x+1)(x^2-4)
=(x^2+x+1)(x+2)(x-2)
8.x(x-1)+y(y+1)-2xy
=x^2-2xy+y^2-x+y
=(x-y)^2-(x-y)
=(x+y-1)(x-y)

2.分解因式：9x的平方-6x-y的平方+4y-3=（3x+y-3)(3x-y+1)

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)

这是初一的？？？