几道初二的因式分解,急用的.谢谢!

(a-b)(x-y)-(b-a)(x+y)......
=(a-b)(x-y)＋(a－b)(x+y).
=(a-b)( x-y＋(x+y).
=2x(a-b)

(a-b)(a^2+9)-6x(b-a)
=(a-b)(a^2+9)＋6x(a-b)
=(a-b)（a^2+9＋6x）
x^2(x-y)+(y-x)
= x^2(x-y)－(x-y)
=(x-y)（x^2－1）
=(x-y)（x＋1）（x－1）

(x^2-y^2)^2-8(x^2+y^2)
好像有问题

4+12(x-y)+9(x-y)^2
=〖3(x-y)＋2〗^2
=（3x－3y＋2）^2

(a-b)(x-y)-(b-a)(x+y)=(a-b)(x-y+x+y)=2x(a-b)

(a-b)(a^2+9)-6a(b-a) =(a-b)(a^2+9+6a)=(a-b)(a+3)(a+3)

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

(x^2-y^2)^2-8(x^2+y^2) =x^4-2x^2*y^2+y^4-8x^2-8y^2....???

4+12(x-y)+9(x-y)^2=[2+3(x-y)]^2=(2+3x-3y)^2