求助几个数学因式分解的题目！急~~~

1. x-y
2. ax-ay+3
3. x-y+3
4.18x²(x-2y)²-24xy(2y-x)²-6x(2y-x)³
=(x-2y)²(18x²-24xy+6x(x-2y))
=(x-2y)²(18x²-24xy+6x²-12xy)
=(x-2y)²(24x²-36xy)
=12x(x-2y)²(2x-3y)
代入x=-3, y= -1
=108

1.x-y 2.ax-ay+3 3.x-y+3 4.原式=12x(2x-3y)(x-2y)§sup2把x=-3 y=-1代入得,原式=108

1.a(x-y)+b(-y+x)-c(x-y)²各项的公因式是（__x-y__)
2.a(x-y)²-3(y-x)=(x-y)(__ax-ay+3__)
3.6(x-y)³+18(y-x)²=6(x-y)²(__x-y-3__)

4.18x^2(x-2y)^2-24xy(2y-x)^2-6x(2y-x)^3
=(2y-x)^2[-18x^2-24xy-6x(2y-x)]
=6x(2y-x)^2[-3x-4y-(2y-x)]
=6x(2y-x)^2(-3x-4y-2y+x)
=-6x(2y-x)^2(3x+4y+2y-x)
=-6x(2y-x)^2(2x+6y)
=-12x(2y-x)^2(x+3y)

-12x(2y-x)^2(x+3y)
=-12*(-3)[2*(-1)-(-3)]^2[(-3)+3*(-1)]
=36*(-2+3)^2*(-3-3)
=36*1*(-6)
=-216

选我 选我哦 (*^__^*) 嘻嘻……只填括号里的哦
1.x—y
2（x—y）（ax-ay+3）
3 4x—4y
4 6x（2y-x）²（3x-4y-2