PREP DS -11 求教

reginaer

11.

If p is a positive odd integer, what is the remainder when p is divided by 4 ?

 

(1) When p is divided by 8, the remainder is 5.

 

(2) p is the sum of the squares of two positive integers.

 

(1) 可以,

 

(2)?/ 怎么算出来, (2) 不行的, 9+4/4.   25+4/4,  余1,  49+4/4, 余 3

 

 可是答案给的是D 啊?

 

 

reginaer

晕~~  , 我做DS 超级不清醒, 谢谢楼上的

chouliulu

49+4/4=53/4=13...1

xiaoxiugirl

p为odd，根据2），可以确定一定是“奇数的平方+偶数的平方”

设p=（2n）^2 +(2m+1)^2