cf天赋点怎么获得最快:趣味数学

来源:百度文库 编辑:杭州交通信息网 时间:2024/05/06 06:12:33
1/1*2=1-1/2;1/2*3=1/2-1/3;1/3*4=1/3-1/4;.......。故1/1*2+1/2*3+1/3*4+.....+1/99*100=1-1/2+1/2-1/3+1/3-1/4+....+1/99-1/100=1-1/100=99/100。仔细观察,求出1/10*11+1/11*12+...1/199*200.
写出过程!!!!!!!

=1/10-1/11+1/11-1/12+1/12-1/13……-1/199+1/199-1/200
=1/10-1/200
=19/200

=1/10-1/11+1/11-1/12+1/12-1/13.....+1/199-1/200
=1/10-1/200
=19/200

=1/10-1/11+1/11-1/12+1/12-1/13.....+1/199-1/200
=1/10-1/200
=19/200