123/1+234/1+345/1+...+99100101/1

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/16 15:44:08

1*2*3/1+2*3*4/1+3*4*5/1+...+99*100*101/1

an=1/2n+1/2(n+2)-1/(n+1)
1/1*2*3+1/2*3*4+1/3*4*5+...+1/99*100*101
=(1/2+1/6-1/2)+(1/4+1/8-1/3)+...+(1/198+1/202-1/100)
=0.5*(1+1/2+...+1/99)+0.5*(1/3+1/4+...+1/101)-(1/2+1/3+1/4+...+1/100)
=0.5*(1+1/2+1/100+1/101)-1/2-1/100
=1/2+1/4+1/200+1/202-1/2-1/100
=1/4+1/200+1/202-1/100
= (5050+ 101+100-202) /20200
=5 049 /20200

1/1*2*3+1/2*3*4+1/3*4*5+...+1/99*100*101 1/1*2*3+1/2*3*4+1/3*4*5+.1/99*100*101 (1+1/1*3)*(1+1/2*4)*(1+1/3*5).(1+1/98*100)*(1+1/99*101) (1+1/1+3)*(1+1/2*4)*(1+1/3*5)*.*(1+1/98*100)*(1+1/99*101) 1*1-2*2+3*3-4*4+...+99*99-100*100+101*101 1*2/1+2*3/1+3*4/1+.100*101/1 1*3/1+3*5/1+5*7/1+.+99*101/1 怎么 1-2+3-4+5-6+...+99-100+101求值 1+(-2)+(+3)+(-4)+(+5)+(-6).(+99)+(-100)+(101) 1+2+3+4+5+6~+99+100+101=? (-1)+2+(-3)+4+(-5)+6+.+(-99)+100+(-101)+102 计算:101-100+99-98+...+5-4+3-2+1 1,2,3,...,99,100； 2,3,4,...,100,101； 4,5,6,...,101,102；...10