1-5/6+7/12-9/20+11/30-13/42+15/56-17/72+19/90 简便计算
答案:2 悬赏:80
解决时间 2021-03-02 15:31
- 提问者网友:相思故
- 2021-03-01 17:34
1-5/6+7/12-9/20+11/30-13/42+15/56-17/72+19/90 简便计算
最佳答案
- 二级知识专家网友:野心和家
- 2021-03-01 17:59
1 - 5/6 + 7/12 - 9/20 + 11/30 - 13/42 + 15/56 - 17/72 + 19/90
= 1 - (3+2)/6 + (4+3)/12 - (5+4)/20 + (6+5)/30 - (7+6)/42 + (8+7)/56 - (9+8)/72 + (10+9)/90
= 1 - 1/2 - 1/3 + 1/3 + 1/4 - 1/4 - 1/5 + 1/5 + 1/6 - 1/6 - 1/7 + 1/7 + 1/8 - 1/8 - 1/9 + 1/9 + 1/10
= 1/2 + 1/10
= 5/10 + 1/10
= 6/10
= 3/5
= 1 - (3+2)/6 + (4+3)/12 - (5+4)/20 + (6+5)/30 - (7+6)/42 + (8+7)/56 - (9+8)/72 + (10+9)/90
= 1 - 1/2 - 1/3 + 1/3 + 1/4 - 1/4 - 1/5 + 1/5 + 1/6 - 1/6 - 1/7 + 1/7 + 1/8 - 1/8 - 1/9 + 1/9 + 1/10
= 1/2 + 1/10
= 5/10 + 1/10
= 6/10
= 3/5
全部回答
- 1楼网友:两不相欠
- 2021-03-01 18:58
1-5/6+7/12-9/20+11/30-13/42+15/56-17/72+19/90
=1-1/2-1/3+1/3+1/4-1/4-1/5+........+1/9+1/10
=1-1/2+1/10
=1/2+1/10
=5/10+1/10
=6/10
=3/5
(5/6=1/2+1/3,7/12=1/3+1/4……)
我要举报
如以上问答内容为低俗、色情、不良、暴力、侵权、涉及违法等信息,可以点下面链接进行举报!
大家都在看
推荐资讯