1...3a^2(x-y)-27(x-y)b^2

1...3a^2(x-y)-27(x-y)b^2 =3(x-y)[a^2-(3b)^2]=3(x-y)(a+3b)(a-3b)2...-4a^3 b^4+16a^2 b^5-16ab^6 =-4ab^4(a^2-4ab+4b^2)=-4ab^4(a-2b)^23...a^2-(b^2+c^2-2bc) =a^2-(b-c)^2 =(a+b-c)(a-b+c)4...(x+2)(x+4)...

3a^2(x-y)-27(x-y)b^2
=3(x-y)(a^2-9b^2)
=3(x-y)(a-3b)(a+3b)
-4a^3 b^4+16a^2 b^5-16ab^6
=-4a b^4(a^2-4a b+4b^2)
=-4a b^4(a-2b)^2
a^2-(b^2+c^2-2bc)
=a^2-(b-c)^2
=(a+b-c)(a...

3(x-y)(a+3b)(a-3b)
-4ab^4(a-2b)^2
(a-b+c)(a+b-c)
2(x+1)(x+2)
3(m-n)(3m+n-3)

3(x-y)(a-3b)(a+3b),-4ab^4(a-2b)^2,(a-b+c)(a+b-c),2(x+2)(x+1)这几个都很一般就不写步骤了。
最后这个要拆添个常数项稍微麻烦点。。=9m^2-6m-3+3+2n-n^2=3(m-1)(3m+1)-(n-3)(n+1)