计算1/2+(1/3+2/3)+(1/4+2/4+3/4)+(1/5+2/5+3/5+4/5)+…

计算1/2+(1/3+2/3)+(1/4+2/4+3/4)+(1/5+2/5+3/5+4/5)+……+(1/60+2/60+……+59/60)

第1个回答  推荐于2020-12-10

追问

能写的在具体点吗

追答

我好像写错了,让我在算算

追问

是不是得90?

追答

差不多是这样,那一步不懂?

计算:1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+(1\/5+2\/5+3\/5+4\/5)+…+(1\/60+2\/...
1\/3+2\/3=1 1\/4+2\/4+3\/4=2\/4+1=1\/2+1 1\/5+2\/5+3\/5+4\/5=(1\/5+4\/5)+(2\/5+3\/5)=1+1 1\/6+2\/6+3\/6+4\/6+5\/6=(1\/6+5\/6)+(2\/6+4\/6)+3\/6=1+1+1\/2 应该能看出规律了吧 那么7为分母的结果为1+1+1 8为分母的结果为1+1+1+1\/2 9的为...

1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+(1\/5+2\/5+3\/5+4\/5)+...+(1\/60+2\/60+3...
所以原式=1\/2+2\/2+3\/2+……+59\/2 =(1+2+……+59)\/2 =59*60\/2\/2 =885

1\/2+1\/3+2\/3加四分之一加四分之二加四分之三加五分之一加五分之二加五...
结果一定是整数 光从分母看,从3到60,奇偶数各为29个 所以所有分母为奇数项的和为(1+29)×29÷2=435 所有偶数项的和为435+29×(1\/2) 又因为一开始就有一个被撇除不看的1\/2,所以偶数项所有的和应该为435+30×(1\/2)=450 1\/2+1\/3+2\/3+1\/4+2\/4+3\/4+1\/5+2\/5+3\/5+4\/...

1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+(1\/5+2\/5+3\/5+4\/5)+...
先总结一下,凡是分母是奇数的,如(1\/3+2\/3)=1 (1\/5+2\/5+3\/5+4\/5)=2,都是整数,且等于(奇数-1)\/2 以此类推,(1\/49+2\/49+…+48\/49)= 24 分母是偶数的,如1\/2=0.5,(1\/4+2\/4+3\/4)=1.5,(1\/6+2\/6+3\/6+4\/6+5\/6)=2.5以此类推,(1\/50+2\/50+…+48\/...

...1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+(1\/5+2\/5+3\/5+4\/5)+...+(1\/50+2\/...
1\/2=1\/2 (1\/3+2\/3)=2\/2 (1\/4+2\/4+3\/4)=3\/2 (1\/5+2\/5+3\/5+4\/5)=4\/2 ……(1\/50+2\/50+...+49\/50)=49\/2 所以原式为1\/2+2\/2+3\/2+4\/2……+49\/2=1225\/2

1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+(1\/5+2\/5+3\/5+4\/5)+...
每个单元是(n-1)\/2,也就是1\/2+。。。+(50-1)\/2 共计(50-1)=49组数相加 首尾的平均数 (1\/2+(50-1)\/2)\/2=50\/4,这样的数有49个 因此总和为 (50\/4)*49 =612.5

1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+……+(1\/50+2\/50+3\/50+……+49\/50) 十 ...
原式=1\/2+(1\/3+2\/3)+...+(1+2+...+n-1)\/n =1\/2+(1\/3+2\/3)+...+(n-1)n\/(2n)=1\/2+(1\/3+2\/3)+...+(n-1)\/2 =(1+2+...+49)\/2 =(1+49)*49\/4 =1225\/2;

1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)...+(1\/50+2\/50...+48\/50+49\/50)
1\/n+2\/n+3\/n+……+(n-1)\/n =[1+2+……+(n-1)]\/n =[n(n-1)\/2]\/n =(n-1)\/2 所以原式=1\/2+2\/2+3\/2+……+49\/2 =(1+2+……+49)\/2 =49*50\/2\/2 =612.5 参考资料:仅供参考,祝您学习进步!

计算:1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+...+(1\/50+2\/50+3\/5
1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+...+(1\/n+2\/n+3\/n+...+(n-1)\/n) n取值2--50 化简为1\/2+(1\/3+1-1\/3)+(1\/4+2\/4+1-1\/4)+...(1\/50+2\/50+3\/50+...24\/50+25\/50+1-24\/50+...+1-3\/50+1-2\/50+1-1\/50)综合分析:当n为偶数时,其各项的和=...

计算1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+...+(1\/40+2\/40+...+39\/40)
1\/n+2\/n+……+(n-1)\/n =[1+2+……+(n-1)]\/n =[n(n-1)\/2]\/n =(n-1)\/2 所以 1\/2+(1\/3+2\/3)+(1\/4+2\/4+3\/4)+...+(1\/40+2\/40+...+39\/40)=(2-1)\/2+(3-1)\/2+……+(40-1)\/2 =(1+2+……+39)\/2 =[39*(39+1)\/2]\/2 =390 ...

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