因式分解①9(x+y)²-12(x+y-1/3) ②8-6x-6y+（x+y）²③xy³-2x²y²+x³y

1、(3x+3y-2)^2
2、(x+y-2)(x+y-4)
3、xy(x-y)^2过程，第3我会做了1、原式=[3(x+y)]^2-12(x+y)+4=[3(x+y)-2]^2=(3x+3y-2)^22、原式=(x+y)^2-6(x+y)+9-1=(x+y-3)^2-1=(x+y-4)(x+y-2)