plz help me to to answer the question,if you do not know the answer,plz answer no~i need the steep~Thanks for your help~
1)Given that the sum of the integers from 1 to n is n(n+1)/2,ie.1+2+3+...+n=n(n+1)/2
(a)Find 1+2+3+...+50
(b)Find 1+2+3+..+100
(c)Find 51+52+53+...+100
(d)Find 21+22+23+...+50
f.2 MATHZ PLZ HELP VERY IMPORTANT
2007-09-25 2:54 am
回答 (2)
2007-09-25 4:13 am
✔ 最佳答案
(a) 50(50+1)/2=1275(b) 100(100+1)/2=5050
(c) 100(100+1)/2-50(50+1)/2 =5050-1275 =3775
(d) 50(50+1)/2 - 20(20+1)/2 =1275-210 =1065
2007-09-25 3:21 am
1) 1275
2) 5050
3) 3785
4) 1065
2) 5050
3) 3785
4) 1065
收錄日期: 2021-04-13 13:36:41
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https://hk.answers.yahoo.com/question/index?qid=20070924000051KK02789