B1: Phân tích đa thức thành nhân tử:
1, a.(a+2b)3-b.(2a+b)3
2, ab.(a+b)-bc.(b+c)+ac.(a-c)
3, a.(b2+c2)+b.(c2+a2)+c.(a2+b2)+2abc
4, (a+b).(a2-b2)+(b+c).(b2-c2)+(c+a).(c2-a2)
5, a3.(b-c)+b3.(c-a)+c3.(a-b)
6, a3.(c-b2)+b3.(a-c2)+c3.(b-a2)+abc.(abc-1)
7, a.(b+c)2.(b-c)+b.(c+a)2.(c-a)+c.(a+b)2.(a-b)
8, a.(b-c)3+b.(c-a)3+c.(a-b)3
9, a2b2.(a-b)+b2c2.(b-c)+c2a2.(c-a)
10, a.(b2+c2)+b.(c2+a2)+c.(a2+b2)-2abc-a3-b3-c3
11, a4.(b-c)+b4.(c-a)+c4.(a-b)