1+3+5+7+9+11+13+15+17+19=?
回答 (16)
2007-03-18 2:51 am
1+3+5+7+9+11+13+15+17+19=100
2007-03-17 8:30 pm
1+3+5+7+9+11+13+15+17+19=100
因為19+1=20,17+3=20,15+5=20,13+7=20,11+9=20
所以=20x5=100
因為19+1=20,17+3=20,15+5=20,13+7=20,11+9=20
所以=20x5=100
2007-03-17 12:00 am
1+3+5+7+...(n-2)+n{n必須是奇數}={(1+n)*[(n-1)/2+1]}/2
1+3+5+7+9+11+13+15+17+19={(1+19)*[(19-1)/2+1]}/2=100
1+3+5+7+9+11+13+15+17+19={(1+19)*[(19-1)/2+1]}/2=100
2007-03-16 7:49 am
1+3+5+7+9+11+13+15+17+19=?
1+19=20
3+17=20
5+15=20
7+13=20
9+11=20
即1+3+5+7+9+11+13+15+17+19
=20x5
=100
1+19=20
3+17=20
5+15=20
7+13=20
9+11=20
即1+3+5+7+9+11+13+15+17+19
=20x5
=100
2007-03-16 6:13 am
咪等於１００lo~~
2007-03-16 5:57 am
首先，要搞到佢唔使進位…咁就容易o的計啦！
姐係：
(1+19)+(3+17)+(5+15)+(7+13)+(9+11)
=20+20+20+20+20
=20ｘ5
=100
姐係：
(1+19)+(3+17)+(5+15)+(7+13)+(9+11)
=20+20+20+20+20
=20ｘ5
=100
參考: 學過奧林匹克Maths 的我+阿sir
2007-03-16 5:49 am
1+3+5+7+9+11+13+15+17+19
=(20)5
=100
because (1+19)+(3+17)+(5+15)+(7+13)+(9+11)
=20(5)
=(20)5
=100
because (1+19)+(3+17)+(5+15)+(7+13)+(9+11)
=20(5)
參考: me
2007-03-16 5:48 am
等於100架^^
2007-03-16 5:47 am
呢到有5個20,所以將5x20就得啦''
2007-03-16 5:43 am
1 + 3 = 4 = 2 * 2
1 + 3 + 5 = 9 = 3 * 3
1 + 3 + 5 + 7 = 16 = 4 * 4
Therefore, 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 = 10 * 10 = 100
1 + 3 + 5 = 9 = 3 * 3
1 + 3 + 5 + 7 = 16 = 4 * 4
Therefore, 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 = 10 * 10 = 100
收錄日期: 2021-04-12 18:48:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070315000051KK04474