數學唔識做,因式分解

1. a6-b6
=(a2)3-(b2)3
=(a2-b2)(a4+a2b2+b4)
=(a-b)(a+b)(a4+a2b2+b4)

2. a6+b6
=(a2)+(b2)3
=(a2+b2)(a4-a2b2+b4)
=(a2+b2) (a4-a2b2+b4)

3. a9-b9
=(a3) 3-(b3) 3
=(a3-b3)(a6+a3b3+b6)
=(a-b)(a2+ab+b2)(a6+a3b3+b6)


4. a12+b12
=(a6) 2+(b6) 2
=(a6+b6)(a12-a6b6+b12)
=(a2+b2) (a4-a2b2+b4) (a12-a6b6+b12)

2009-06-26 23:35:42 補充：
1. a^6-b^6

=(a^2)^3-(b^2)^3

=(a^2-b^2)(a^4+a^2b^2+b^4)

=(a-b)(a+b)(a^4+a^2b^2+b^4)

=(a-b)(a+b)(a^2+ab+b^2)(a^2-ab+b^2)