1+2+3+...+56?
回答 (5)
2017-04-22 7:17 pm
有一種思路告訴你:
1+56=57
2+55=57
...
27+30=57
28+29=57
所以28*57=1596
1+56=57
2+55=57
...
27+30=57
28+29=57
所以28*57=1596
2017-04-20 1:07 pm
1596
use 1+56
2+55
..............
therefore 57(56+1)
has 28 groups (56/2)
so 57x28=1596
use 1+56
2+55
..............
therefore 57(56+1)
has 28 groups (56/2)
so 57x28=1596
2017-04-04 7:48 pm
(1+56)56÷2=1596
2017-03-26 10:35 am
〔(56+1)×56〕/2=1596
2017-03-23 6:16 pm
((1+56)*((56-1)+1))/2
=1596
=1596
收錄日期: 2021-04-18 16:06:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20170323101257AATtLTL