唔該幫我......
1+2+3+...+99+100+99+88...+2+1=?
唔該幫我......
2006-11-30 1:48 am
回答 (5)
2006-11-30 2:52 am
1+2+3+...+99+100+99+98...+2+1
=(1+100)*100/2+(1+99)*99/2
=101*100/2+100*99/2
=5050+4950
=10000
=(1+100)*100/2+(1+99)*99/2
=101*100/2+100*99/2
=5050+4950
=10000
2006-11-30 2:02 am
=1+2+3+...+99+100 +1+2+3+...99
=(1+100)X100/2+(1+99)X99/2
=5050+4950
=10000
Other way to calculate
1+2+3+...+100=5050
5050X2-100
=10000
=(1+100)X100/2+(1+99)X99/2
=5050+4950
=10000
Other way to calculate
1+2+3+...+100=5050
5050X2-100
=10000
2006-11-30 2:01 am
(1+100)×(100÷2)+(1+99)×(99÷2)
=5050+4950
=10000
=5050+4950
=10000
2006-11-30 2:00 am
=(1+100)*100/2+(1+99)*99/2
=5050+4950
=10000
=5050+4950
=10000
2006-11-30 1:57 am
係10050
收錄日期: 2021-04-12 18:13:07
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061129000051KK02548