數學問題 1+2+3+4+5...+100答案及過程
回答 (13)
2007-10-16 4:32 am
✔ 最佳答案
1 + 2 + 3 + 4 + 5 + 6 + .... + 100公式是： (頭加尾) 乘 項數(即總共有多少數字) 除 2
可以理解為：一個直角三角形數型，從1 開始到100 遞增，
亦可以理解為 (1 + 100) + (2 + 99) + (3 + 98)....( 55 + 56)
全部 blankets' value 都是101，而總共有 50 對
( 100【項數】 之中2個一對，所以除2，等於50)
101 x 50 = 5050
2007-10-15 20:34:31 補充：
上面（ 55 56)這裡打錯了，應該是 (50 51)....
2007-10-16 5:18 am
1+2+3+4+5...+100
=100+50+(1+99)+(2+98)+(3+97)...(41+49)
=100+50+49(100)
=100+50+4900
=5050
=100+50+(1+99)+(2+98)+(3+97)...(41+49)
=100+50+49(100)
=100+50+4900
=5050
2007-10-16 4:19 am
(1+99)+(2+98)+......+(49+51)......
=100x49+100+50
=4900+100+50
=5000+50
=5050
=100x49+100+50
=4900+100+50
=5000+50
=5050
參考: me
2007-10-16 4:19 am
1+100=101
2+99=101
.................
.
.
.
.
.
.
.
.
.
.
.
49+52=101
50+51=101
101*50=5,050
2+99=101
.................
.
.
.
.
.
.
.
.
.
.
.
49+52=101
50+51=101
101*50=5,050
2007-10-16 4:19 am
1+100=101
2+99=101
3+98=101
.
.
.
.
50+51=101
共有50個101,再相x
50x101=5050
1+2+3+4+5...+100=5050
2+99=101
3+98=101
.
.
.
.
50+51=101
共有50個101,再相x
50x101=5050
1+2+3+4+5...+100=5050
2007-10-16 4:19 am
(1+100)x100
------------------
2
=101x50
=5050
====
Hope it can help you!
------------------
2
=101x50
=5050
====
Hope it can help you!
2007-10-16 4:18 am
1+2+3+4+5...+100
=(1+99)+(2+98).....+100+50
=50x100+50
=5050
=(1+99)+(2+98).....+100+50
=50x100+50
=5050
2007-10-16 4:18 am
係A.P.
首項 = 1
等差 = 1
項數 = 100
s(n) = n/2(2a+ (n-1)d) = 50 (2(1)+99(1)) = 5050
首項 = 1
等差 = 1
項數 = 100
s(n) = n/2(2a+ (n-1)d) = 50 (2(1)+99(1)) = 5050
2007-10-16 4:17 am
1+2+3+4+5...+100
=(1+100)+(2+99)+(3+98)...........
=(1+100)*50
=5050
=(1+100)+(2+99)+(3+98)...........
=(1+100)*50
=5050
收錄日期: 2021-04-12 01:40:07
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071015000051KK03450