已知N是整數。求證
a.18N+12是6的倍數。
b.3(2N-1)+1是偶數。
請高手指點一條數
2008-09-09 10:55 pm
回答 (2)
2008-09-09 11:11 pm
✔ 最佳答案
Method 1this is very simple to evaluate for this question
(a) 18n + 12 = 6 (3n + 2) >>> factor of 6
(b) 3(2n - 1 ) +1 = 6n - 3 + 1 = 6n - 2 = 2 (3n-1) >>>>> factor of 2
Method 2
using M.I.
參考: hope to help you
2008-09-09 11:53 pm
a18N+12=6(6N+2) so18N+12是6的倍數。
b首先2N必定是偶數,-1後是單數,X3後又是單數,+1後是偶數...
請多多支持
b首先2N必定是偶數,-1後是單數,X3後又是單數,+1後是偶數...
請多多支持
參考: ME
收錄日期: 2021-04-23 23:11:38
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