一道小学数学题:1/(1*3)+1/(3*5)+1/(5*7)+1/(7*9)+......1/(97*99) 请简便解答?

如题所述

第1个回答  2011-07-19
原式=1/2[(1-1/3)+(1/3-1/5)+(1/5-1/7)+(1/7-1/9)+……+(1/97-1/99)]
=1/2[1-1/99]
=1/2*(98/99)
=49/99
第2个回答  2011-07-19
2/(1*3)=1-1/3
1/(1*3)=(1-1/3)*1/2
也就是先将原式乘以2计算,然后再除以2,这样计算起来比方便
第3个回答  2011-07-19
65/99
第4个回答  2011-07-19
1/(1*3)+1/(3*5)+1/(5*7)+1/(7*9)+......1/(97*99)
=(1/1-1/3+1/3-1/5+……+1/97-1/99)*(1/2)
=(1-1/99)*(1/2)
=49/99本回答被提问者采纳

一道小学数学题:1\/(1*3)+1\/(3*5)+1\/(5*7)+1\/(7*9)+...1\/(97*99...
原式=1\/2[(1-1\/3)+(1\/3-1\/5)+(1\/5-1\/7)+(1\/7-1\/9)+……+(1\/97-1\/99)]=1\/2[1-1\/99]=1\/2*(98\/99)=49\/99

1\/(1*3)+1\/(3*5)+1\/(5*7)+1\/(7*9)+1\/(9*11)=?需要详细的计算步骤。
1\/(1*3)+1\/(3*5)+1\/(5*7)+1\/(7*9)+1\/(9*11)= =(1\/1-1\/3)\/2+(1\/3-1\/5)\/2+...+(1\/9-1\/11)\/2 =(1\/1-1\/3+1\/3-1\/5...+1\/9-1\/11)\/2 =(1-1\/11)\/2 =5\/11

1\/1×3+1\/3×5+1\/5×7…+1\/97×99得多少,加过程。
1\/(1×3)+1\/(3×5)+1\/(5×7)…+1\/(97×99)的结果等于49\/99。解:1\/(1×3)+1\/(3×5)+1\/(5×7)…+1\/(97×99)=1\/2*(1-1\/3)+1\/2*(1\/3-1\/5)+1\/2*(1\/5-1\/7)+...+1\/2*(1\/97-1\/99)=1\/2*((1-1\/3)+(1\/3-1\/5)+(1\/5-1\/7)+...+(1\/97-1\/...

1\/1*3+1\/3*5+1\/5*7+...+1\/99*101=? (要简便)
解:令a1=1\/(1*3)、a2=1\/(3*5)、a3=1\/(5*7)、、an=1\/(99*101)。可得,an=1\/((2n-1)*(2n+1))当n=1,a1=1\/(1*3),当n=2,a2=1\/(3*5),则当n=50时,a50=1\/(99*101)所以1\/(1*3)+1\/(3*5)+1\/(5*7)+...+1\/(99*101)为数列an前50项的和S50。又an=1\/...

1\/3+1\/15+1\/35+1\/63+1\/99=? 要用简便方法计算 告诉我过程。我记得好像要...
5\/11。解答过程如下:=1\/(1*3)+1\/(3*5)+1\/(5*7)+1\/(7*9)+1\/(9*11)=(1\/1-1\/3+1\/3-1\/5+1\/5-1\/7+1\/7-1\/9+1\/9-1\/11)*1\/2 =(1-1\/11)*1\/2 =10\/11*1\/2 =5\/11

1\/(1×3)+1\/(3×5)+1\/(5×7)+1\/(7×9)+...+1\/(19×21)简便计算怎么做...
1\/(1×3)+1\/(3×5)+1\/(5×7)+1\/(7×9)+...+1\/(19×21 =1\/2x(1-1\/3)+1\/2x(1\/3-1\/5)+...+1\/2x(1\/19-1\/21)=1\/2x(1-1\/21)=10\/21

1\/1*3+1\/3*5+1\/5*7+1\/7*9+19*11+...+1\/1995*1997+1\/1997*1999的简便算 ...
观察数字,你会发现这样的规律:1\/1*3=(1-1\/3)*0.5 1\/3*5=(1\/3-1\/5)*0.5 1\/5*7=(1\/5-1\/9)*0.5 1\/7*9=(1\/7-1\/9)*0.5 ...那么1\/1*3+1\/3*5+1\/5*7+1\/7*9+19*11+...+1\/1995*1997+1\/1997*1999 =((1-1\/3)+(1\/3-1\/5)+(1\/5-1\/9...

数学题1\/1*3+1\/3*5+1\/5*7+...1\/97*99+1\/99*101=?谢谢!
所以1\/3+1\/3*5+1\/5*7...1\/99*101 =[(1-1\/3)+(1\/3-1\/5)+...+(1\/99-1\/101)]\/2 =(1-1\/101)\/2 =50\/101 性质1 等式两边同时加上(或减去)同一个整式,等式仍然成立。若a=b 那么a+c=b+c 性质2 等式两边同时乘或除以同一个不为0的整式,等式仍然成立。若a=b 那么有a...

1\/3×5+1\/5×7+1\/7\/9十……十1\/97×99=?(用简便算法,地等式)
十1\/97×99=?(用简便算法,地等式)  我来答 6个回答 #热议# 孩子之间打架 父母要不要干预? 17考研a 2015-06-01 · TA获得超过242个赞 知道小有建树答主 回答量:419 采纳率:21% 帮助的人:105万 我也去答题访问个人页 关注 展开全部 追答 希望我的回答能帮助到你,望采纳 本回答...

1\/(1+3)+1\/(3+5)+1\/(5+7)…+1\/(99+101)=( )简便计算
1\/(1+3)+1\/(3+5)+1\/(5+7)…+1\/(99+101)=1\/4+1\/8+1\/12+.+1\/200 =1\/4(1+1\/2+1\/3+...+1\/50)括号内为发散级数,无公式求解 只有近似值,结果是4.4992 是无法用分数表示的 所以原题结果为:4.4992\/4=1.1248

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