MI (pure)!!!!!!!!!!!!!!!!!!!!!

2010-08-16 1:41 am
有數題MI 想問
1)1^3 +2^3+3^3+....+(2n)^3=n^2(2n+1)^2
2)n X1 +(n-1) X2 + (n-2) X3 +....+ 3X (n-2) +2 X (n-1) +1 Xn =1/6n(n+1)(n+2)
希望大家可以解答我既問題
THX
THX
THX

回答 (1)

2010-08-16 3:12 am
✔ 最佳答案
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2010-08-15 19:13:02 補充:
http://img709.imageshack.us/img709/4955/32043243.png


收錄日期: 2021-04-23 23:22:29
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