原式=1/2+1/6+1/12+........1/110=1/2+(1/2-1/3)+(1/3-1/4)++...........+(1/10-1/11)=1-1/11=10/11
0
原式=1/2+1/6+1/12+........1/110=1/2+(1/2-1/3)+(1/3-1/4)++...........+(1/10-1/11)=1-1/11=10/11