查人人中国名人网下载拼单词图软件:小学简算题
来源：百度文库 编辑：查人人中国名人网 时间：2024/05/03 08:58:33
20042004*20042003-20042005*20042002
1+1/15+3+1/35+5+1/63+7+1/99+9+1/143+11+1/195
1+1/15+3+1/35+5+1/63+7+1/99+9+1/143+11+1/195
(1)20042004*20042003-20042005*20042002
=(20042005-1)*20042003-20042005*20042002
=20042005*20042003-20042005*20042002-20042003
=20042005*(20042003-20042002)-20042003
=20042005-20042003
=2
(2)1+1/15+3+1/35+5+1/63+7+1/99+9+1/143+11+1/195
=(1+3+5+7+9+11)+[1/(3*5)+1/(5*7)+1/(7*9)+1/(9*11)+1/(11*13)+1/(13*15)]
=[1+5+(3+7)+(9+11)]+(1/2)*(1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11+1/11-1/13+1/13-1/15)
=(6+10+20)+(1/2)*(1/3-1/15)
=36+2/15
=542/15
(供参考)
20042004*20042003-20042005*20042002=20042004*20042003-20042004*20042002-20042002=20042004-20042002=2
1+1/15+3+1/35+5+1/63+7+1/99+9+1/143+11+1/195=（分数裂项）1+3+5+7+9+11+（1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11+1/11-1/13+1/13-1/15）/2=36+(1/3-1/15)/2=36+2/15=36又2/15