幫我計算
2-(分母3x4分子1+分母4x5分子1+分母5x6分子1+.............+分母201x202分子1)=???
好難!!@_@
答對就會是最佳回答!!!!!!!!!!!!!!!!!!!!!!
I don”t no 這條數學題!! fast~~~
2009-03-21 7:20 am
回答 (3)
2009-03-21 7:31 am
✔ 最佳答案
2 - ( 1/3*4 + 1/4*5 + 1/5*6 + ... + 1/201*202)= 2 - [(1/3 - 1/4) + (1/4 - 1/5) + (1/5 - 1/6) + ... + (1/201 - 1/202)]
= 2 - [1/3 + ( 1/4 - 1/4) + (1/5 - 1/5) + ... (1/201 - 1/201) - 1/202]
= 2 - (1/3 - 1/202)
= 2 - ( 202/606 - 3/606)
= 2 - 199/606
= 1013/606
2009-03-20 23:34:24 補充：
1 / a(a+1)
= 1/a - 1/(a+1)
2009-03-28 12:41:49 補充：
怎麼那麼多抄襲的???!!!!!
2009-03-26 3:19 am
2 - ( 1/3*4 + 1/4*5 + 1/5*6 + ... + 1/201*202)
= 2 - [(1/3 - 1/4) + (1/4 - 1/5) + (1/5 - 1/6) + ... + (1/201 - 1/202)]
= 2 - [1/3 + ( 1/4 - 1/4) + (1/5 - 1/5) + ... (1/201 - 1/201) - 1/202]
= 2 - (1/3 - 1/202)
= 2 - ( 202/606 - 3/606)
= 2 - 199/606
= 1013/606/1+407/606
= 2 - [(1/3 - 1/4) + (1/4 - 1/5) + (1/5 - 1/6) + ... + (1/201 - 1/202)]
= 2 - [1/3 + ( 1/4 - 1/4) + (1/5 - 1/5) + ... (1/201 - 1/201) - 1/202]
= 2 - (1/3 - 1/202)
= 2 - ( 202/606 - 3/606)
= 2 - 199/606
= 1013/606/1+407/606
2009-03-25 3:11 am
2 - ( 1/3x4 + 1/4x5 + 1/5x6 + ..... + 1/201x202)
= 2 - [(1/3 - 1/4) + (1/4 - 1/5) + (1/5 - 1/6) + ..... + (1/201 - 1/202)]
= 2 - [1/3 + ( 1/4 - 1/4) + (1/5 - 1/5) + ..... (1/201 - 1/201) - 1/202]
= 2 - (1/3 - 1/202)
= 2 - ( 202/606 - 3/606)
= 2 - 199/606
= 1013/606//
= 2 - [(1/3 - 1/4) + (1/4 - 1/5) + (1/5 - 1/6) + ..... + (1/201 - 1/202)]
= 2 - [1/3 + ( 1/4 - 1/4) + (1/5 - 1/5) + ..... (1/201 - 1/201) - 1/202]
= 2 - (1/3 - 1/202)
= 2 - ( 202/606 - 3/606)
= 2 - 199/606
= 1013/606//
收錄日期: 2021-04-21 22:07:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090320000051KK01901