(a+b)的3次方、4次方怎么算?

2025-03-20 09:32:18
推荐回答(3个)
回答1:

(a+b)^3
=(a+b)(a+b)^2
=(a+b)(a^2+2ab+b^2)
=a^3+b^3+3ab^2+3a^2b
(a+b)^4
=(a+b)^2(a+b)^2
=(a^2+2ab+b^2)(a^2+2ab+b^2)
=a^4+4a^3b+6a^2b^2+4ab^3+b^4

原先上面的“精彩回答“是错的!

回答2:

(a+b)^3
=(a+b)(a+b)^2
=(a+b)(a^2+2ab+b^2)
=a^3+b^3+3ab^2+3a^2b

(a+b)^4
=(a+b)^2(a+b)^2
=(a^2+2ab+b^2)(a^2+2ab+b^2)
=a^4+4a^3b^3+6a^2b^2+4ab^3+b^4

回答3:

(a+b)^3
=(a+b)(a+b)^2
=(a+b)(a^2+2ab+b^2)
=a^3+b^3+3ab^2+3a^2b
(a+b)^4
=(a+b)^2(a+b)^2
=(a^2+2ab+b^2)(a^2+2ab+b^2)
=a^4+4a^3b^3+6a^2b^2+4ab^3+b^4