输血 JJ 148 求助

liuyinghong

148.m是正整数，r是(m+1)(m-1)除以24的余数, 问r是多少？
1）m不是2的倍数
2）m不是3的倍数

huangsiyan

假设 m=1 (不是2的倍数 不是3的倍数)
(m+1)(m-1)/24=0  r=0

pangpangshin

1]     3------2*4     5---4*6   
2]     4-----3*5      5---4*6

[1]+[2]:     5---4*6      7----6*8   11-----10*12  

when m is not multiple of 2, then (m+1)*(m-1)is multiple of 4.

and it seems when m is neither multiple of 2 nor multiple of 3. it appears to

be the multiple of 6........