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)
hu hu hu giúp mk vs
mai mk đi học rùi hu hu hu
\(1.a\left(a+2b\right)^3-b\left(2a+b\right)^3\)
=\(a\left(a^3+6a^2b+12ab^2+8b^3\right)-b\left(8a^3+12a^2b+6ab^2+b^3\right)\)
=\(a^4+6a^3b+12a^2b^2+8ab^3-8a^3b-12a^2b^2-6ab^3-b^4\)
=\(a^4-b^4\)=\(\left(a^2-b^2\right)\left(a^2+b^2\right)\)
\(\text{2, ab.(a+b)-bc.(b+c)+ac.(a-c)}\)
=\(a^2b+ab^2-b^2c-bc^2-c^2a+ca^2+abc-abc\)
=\(\left(a-b\right)\left(b+c\right)\left(c+a\right)\)
Các câu 3;4 tương tự
