小弟不才,3Q!1+(1/1+2)+(1/1+2+3)+.+(1/1+2+3.+100)=?/是分号，括号可以忽略

利用：1/(1+2+3+.+n)=2/n(n+1)
1/n(n+1)=1/n - 1/(n+1)
1=2/(1×2) =2(1/1 - 1/2)
1/(1+2) =2/(2×3)=2(1/2 - 1/3)
1/(1+2+3) =2/(3×4)=2(1/3 - 1/4)
······
1/(1+2+3.+100)=2/(100×101)=2(1/100 - 1/101)
原式=2(1/1 - 1/2)+2(1/2 - 1/3)+2(1/3 - 1/4)+····+2(1/100 - 1/101)
=2(1/1 - 1/101)
=200/101