1+2+3+……+n=n(n+1)/21/[n*(n+1)]=1/n-1/(n+1)原式=1/[(1*2)/2]+1/[(2*3)/2+1/[(3*4)/2]+……+1/[(50*51)/2]=2(1-1/2+1/2-1/3+1/3-1/4+……+1/50-1/51)=2(1-1/51)=100/51
楼主知道“1/1+2+3+4+。。。+50”等于几不？
