1/2+(1/3+2/3)+(1/4+2/4+3/4)+...+(1/60+2/60+...+59/60)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 11:32:32
![1/2+(1/3+2/3)+(1/4+2/4+3/4)+...+(1/60+2/60+...+59/60)](/uploads/image/z/13198153-49-3.jpg?t=1%2F2%2B%281%2F3%2B2%2F3%29%2B%281%2F4%2B2%2F4%2B3%2F4%29%2B...%2B%281%2F60%2B2%2F60%2B...%2B59%2F60%29)
1/2+(1/3+2/3)+(1/4+2/4+3/4)+...+(1/60+2/60+...+59/60)
1/2+(1/3+2/3)+(1/4+2/4+3/4)+...+(1/60+2/60+...+59
/60)
1/2+(1/3+2/3)+(1/4+2/4+3/4)+...+(1/60+2/60+...+59/60)
=1/2+1+1+1/2+2+2+1/2+3+3+1/2+...+29+29+1/2=30*1/2+[(1+29)*29]/2*2=15+30*29=885