1+2+3+4+5+.......+11111+...........1 =?
Not use clculator!!!!!!!!!!!!!!!!!!!!!!
who kown this maths
2006-12-01 6:53 am
回答 (2)
2006-12-01 7:00 am
✔ 最佳答案
1+2+3+4+5+.......+11 111+...........1 = =(1+2+3...+11111)+(11110+11109...+1)
=(11111)(11111+1)/2+(11110)(11110+1)/2
=61732716+61721605
=123454321
2006-12-01 7:06 am
1 + 2 + 3 + 4 + 5 + ... + 11111 + ... + 1
= 1 + 2 + 3 + 4 + 5 + ... + 11110 + 11111 + 11110 + 11109 + ... + 1
= (1+11110) + (2+11109) + (3+11108) + ... + (11109+2) + (11110+1) + 11111
= 11111 x 11111
= 123454321
= 1 + 2 + 3 + 4 + 5 + ... + 11110 + 11111 + 11110 + 11109 + ... + 1
= (1+11110) + (2+11109) + (3+11108) + ... + (11109+2) + (11110+1) + 11111
= 11111 x 11111
= 123454321
收錄日期: 2021-04-12 22:31:59
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061130000051KK04646