哪位有更好的办法呀！！GWD-4-35

XIAOXIANGXI

3-35. if n is a positive integer, which of the following is a possible value of |56-5n|?

 - I just simply put every answer to the equation for testing, which i think is quite awkward.....so anybody has a better idea?

smalllittle

就5个选项，都试一下很快的。如果一定要研究的话,可以用n=12做分界，去掉绝对值，

得出 该绝对值的两个等式：

n<12 时，值为 5P+1     10=>p>=0

n>=12时 值为 5k+4  k>=1

不过，我觉得还不一定有代进去快