=（1-1/2-1/4-1/8）+（1/3-1/6+1/9）+（1/5-1/10）+1/7
=1/8+5/18+1/5+1/7
=13/40+53/126
=1879/2520
=1/2+1/12+1/30+1/56+1/90
=(1260+210+84+45+28)/2520
=1627/2520本回答被提问者采纳
=1+1/3+1/5+1/7+1/9-1/2(1+1/2+1/3+1/4+1/5)
=1/2(2+2/3+2/5+2/7+2/9)-1/2(1+1/2+1/3+1/4+1/5)
=1/2(1/4+1/3+1/5+2/7+2/9)
=1/6+1/7+1/8+1/9+1/10
1-1\/2+1\/3-1\/4+1\/5-1\/6+1\/7-1\/8+1\/9-1\/10+1\/11-1\/12
一就是淡定慢慢算，，可以求数列1\/n的和与1\/2n的和作差吧
求助一道数学题:1-1\/2+1\/3-1\/4+1\/5-1\/6+1\/7-1\/8+1\/9……+1\/19-1\/...
1-1\/2+1\/3-1\/4+...+1\/19-1\/20=(1-1\/2+1\/3-1\/4+1\/5-1\/6+1\/7-1\/8+1\/9-1\/10)-(1\/12+1\/14+1\/16+1\/18+1\/20)+(1\/11+1\/13+1\/15+1\/17+1\/19)=1\/11+(1\/3-1\/6-1\/12)+1\/13+(1\/7-1\/14)+1\/15+(1-1\/2-1\/4-1\/8-1\/16)+1\/17+(1\/9-1\/18)+...
1-1\/2+1\/3-1\/4+1\/5-1\/6+1\/7-1\/8 前n项和
解答：Sn=1-1\/2+1\/3-1\/4+1\/5-1\/6+1\/7-1\/8+.+1\/(2n-1)-1\/2n 没有求和公式，但是如果 n 趋于 +∞ 时，lim（n->∞) sn = ln2 如果一个数列{an}，与首末项等距的两项之和等于首末两项之和，可采用把正着写与倒着写的两个和式相加，就得到一个常数列的和。
1+1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+1\/8+1\/9+1\/10=多少
计算1+1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+1\/8+1\/9+1\/10的过程如下：首先，我们可以通过拆分求和的方法简化计算：= 1 + (1\/2 + 1\/3 + 1\/6) + (1\/4 + 1\/5 + 1\/10) + 1\/7 + 1\/8 + 1\/9 = 1 + 1 + (1\/2 + 1\/3 - 1\/6) + (1\/4 + 1\/5 + 1\/10)= 1 +...
1+1\/3-1\/2+1\/4-1\/3+1\/5-1\/4+1\/6-1\/5+1\/7-1\/6+1\/8-1\/7+1\/9-1\/8+1\/1...
相减的项也写在一块，就能看出来了。原式 = 1 + 1\/3 + 1\/4 + 1\/5 + 1\/6 + 1\/7 + 1\/8 + 1\/9 + 1\/10 - 1\/2 - 1\/3 - 1\/4 - 1\/5 - 1\/6 - 1\/7 - 1\/8 - 1\/9 = 1 + 1\/10 - 1\/2 = 1\/2 + 1\/10 = 3\/5 希望对你有帮助，新年快乐~...
1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+1\/8+1\/9+1\/10+...1\/100这道题怎样简算
他的方法很简单： 1 +1\/2+1\/3 +1\/4 + 1\/5+ 1\/6+1\/7+1\/8 +... 1\/2+1\/2+(1\/4+1\/4)+(1\/8+1\/8+1\/8+1\/8)+... 注意后一个级数每一项对应的分数都小于调和级数中每一项，而且后面级数的括号中的数值和都为1\/2，这样的1\/2有无穷多个，所以后一个级数是趋向无穷大的，...
1+1\/2-1\/3+1\/4-1\/5+1\/6-1\/7+1\/8-1\/9+1\/10-1\/11+1\/12 等于多少 要分数的...
原式=1+1\/2+1\/4+1\/6+1\/8+1\/10+1\/12 -1\/3-1\/7-1\/9-1\/11 =1+(6+3+2+1)\/12+(5+4)\/40 -(3+1)\/9-(11+7)\/77 =1+1+9\/40-4\/9-18\/77 =9\/40+5\/9+59\/77 =(9×9×77+5×40×77+59×40×5)\/(360×77)=33437\/27720 =1+5717\/27720 ...
六年级奥数求全解过程1-2分之1+3分之1-4分之1+...+19分之1-20分之1+...
=1-1\/2+1\/3-1\/4+1\/5-(1\/3+1\/4+1\/5)=1-1\/2-1\/4-1\/4=0 所以这两个式子相等。第二问我看了下，上面虽有作解答，但是没有简单的办法。现解答如下。1\/100+1\/101+```+1\/119+1\/120 =(1\/100+1\/101+```+1\/110)+( 1\/111+1\/112+```+1\/120)>11\/110+10\/120 =1\/10...
1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+……1\/99有简便方法吗
正整数倒数称为调和数列，迄今为止，数学家们尚未找到求和公式。因此，通常是编程来求解，或者用网络计算器。计算结果和fortran代码如下：
1+1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+1\/8+1\/9+1\/10。计算结果。
1+1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+1\/8+1\/9+1\/10 =1+(1\/2+1\/3+1\/6)+(1\/4+1\/5+1\/10)+1\/7+1\/8+1\/9 =1+1+11\/20+1\/8+1\/7+1\/9 =1+1+27\/40+1\/9+1\/7 =1+1+283\/360+1\/7 =1+1+2341\/2520 =1+4861\/2520 ≈2.92896 ...
