1+1\/1+2+1\/1+2+3+...+1\/1+2+3+...+99 等于多少 请写出详细的过程与算...
所以 1+1\/1+2+1\/1+2+3+...+1\/1+2+3+...+99 =2\/(1*2)+2\/(2*3)+...+2\/(99*100)=2(1-1\/2+1\/2-1\/3+...+1\/99-1\/100)=2*99\/100 =99\/50
奥数题1+1\/1+2+1\/1+2+3+1\/1+2+3+4+……+1\/1+2+3+4+5+……100
1+1\/(1+2)+1\/(1+2+3)+1\/(1+2+3+4)+……+1\/(1+2+3……+n)= 1+1\/[(1+2)×2÷2]+1\/[(1+3)×3÷2]+……+1\/[(1+n)×n÷2]——① = 2\/2+2\/(1+2)×2+2\/(1+3)×3+……+2\/(1+n)×n——② = 2×[1\/2+1\/2-1\/3+1\/3-1\/4+……+1\/n-1\/(...
1+1\/1+2+1\/1+2+3+...+1\/1+2+3+4+...+99+100
1+1\/1+2+1\/1+2+3+1\/1+2+3+4+...1\/1+2+3+...+100 =1+1\/[(1+2)×2÷2]+1\/[(1+3)×3÷2]+1\/[(1+4)×4÷2]+...1\/[(1+100)×100÷2]=1+2\/(1+2)×2+2\/(1+3)×3+2\/(1+4)×4+...2\/(1+100)×100 =1+2×(1\/2-1\/3+1\/3-1\/4+1\/4-1\/5...
1+1\/(1+2)+1\/(1+2+3)+...+1\/(1+2+3...+99)
1+1\/(1+2)+1\/(1+2++3)+……+1\/(1+2+3+……+99)=2*【1\/2+1\/2*(1+2)+1\/2*(1+2++3)+……+1\/2*(1+2+3+……+99)】=2*【1-1\/2+1\/2-1\/3+1\/3-1\/4+……+1\/99-1\/100】=2*【1-1\/100】=2-1\/50 =99\/50 =1.98 ...
1+1\/1+2+1\/1+2+3+1\/1+2+3+4+...+1\/1+2+3+...+100这道数学题怎么做,尽量...
化减:2\/1*2+2\/2*3+2\/3*4+…然后列项:(2\/1-2\/2)+(2\/2-2\/3)…然后化简:2\/1-2\/101=200\/101 如果取极限得2
1+1\/(1+2)+1\/(1+2+3)+…+1\/(1+2+3+…100)=
第二种:因为:1+2=2*3\/2 1+2+3=3*4\/2 1+2+3+4=4*5\/2 1+2+3+……+100=100*101\/2 所以,1+1\/(1+2)+1\/(1+2+3)+1\/(1+2+3+4)+...+1\/(1+2+3+...+2006)=1+2\/(2*3)+2\/(3*4)+2\/(4*5)+……+2\/(100*101)=2[(1\/2+1\/(2*3)+1\/(3*...
1+1\/1+2+1\/1+2+3+1\/1+2+3+4+...+1\/1+2+3+...+10怎么算
1+2=2x3\/2 1+2+3=3x4\/2 1+2+3+4=4x5\/2 1+2+……+ n-1 + n =(n-1)n\/2 1+1\/1+2+1\/1+2+3+1\/1+2+3+4+...+1\/1+2+3+...+10 =1+2 (1\/2x3 + 1\/3x4 + ……+ 1\/10x11)=1+2(1\/2 -1\/3+1\/3-1\/4+……+1\/9-1\/10+1\/10-1\/11)=1+2(1\/2 ...
1 + 1\/1+2 + 1\/1+2+3 + 1\/1+2+3+4 + …… +1\/1+2+3+……+50
这个我们先考查他的通项为 有1+2+3+……+n=n(1+n)\/2 an=2\/n(n+1)=2[1\/n-(1\/n+1)]那么他们的和就是2(1-1\/2+1\/2-1\/3+1\/3-1\/4+……+1\/50-1\/51)=2(1-1\/51)=100\/51
1+1+2\/1+1+2+3\/1+1+2+3+4+\/1+...+1+2+3+...+n\/1=?
应该是:1+1\/(1+2)+1\/(1+2+3)+1\/(1+2+3+4)+...+1\/(1+2+3+...+n)通项是:1\/(1+2+3+...+n)=2\/(n(n+1))=2(1\/n-1\/(n+1))所以,原式= 2(1\/1-1\/2)+2(1\/2-1\/3)+...+2(1\/n-1\/(n+1))去括号后,除了第一项和最后一项,其他项可以都可以消去,有...
(1\/1+2)+(1\/1+2+3)+(1\/1+2+3+4)+...+(1\/1+2+3+...+99)=?
1\/(1+2+3)=2*(1\/3-1\/4)1\/(1+2+3+4)=2*(1\/4-1\/5)………1\/(1+2+……+k)=2*【1\/k-1\/(1+k)】………1\/(1+2+3+...+99)=2*(1\/99-1\/100)连加得1\/(1+2)+1\/(1+2+3)+1\/(1+2+3+4)+...+1\/(1+2+3+...+99)=2*(1\/2-1\/3+1\/3-1\/4...