4题20分哦 因式分解1-3(x-y)+3(x-y)^2-(x-y)^3 a^2+b^2+4a-4b-2ab+4 (x+y)^2+(x+m)^2-(m+n)^2-(y+n)^2 a^2(b^2-c^2)-c^2(b-c)(a+b)
问题描述：
4题20分哦 因式分解
1-3(x-y)+3(x-y)^2-(x-y)^3 a^2+b^2+4a-4b-2ab+4 (x+y)^2+
(x+m)^2-(m+n)^2-(y+n)^2 a^2(b^2-c^2)-c^2(b-c)(a+b)
答
1-3(x-y)+3(x-y)^2-(x-y)^3=(1-x+y)^3
a^2+b^2+4a-4b-2ab+4=(a-b+2)^2
(x+y)^2+(x+m)^2-(m+n)^2-(y+n)^2 =2(x+y+m+n)(x-n)
a^2(b^2-c^2)-c^2(b-c)(a+b) =(b-c)(a-c)(ac+ab-bc)
答
(1-(x-y))^3=(1-X+Y)^3
(A-B)^2+4(A-B)+4=(A-B+2)^2
2(X-N）（X+Y+M+N)
(A-C)(b-c)(AB+BC+AC)