都是书后的题..还请高人们指点迷津阿....拜谢~
Section1 :
1.证明假如a|b 并且a>0,那么(a,b)=a
2.证明((a,b),b)=(a,b)
3.假如 x平方+ax+b=0有一个整数根,show那个整数根divides(整除) b
4.假如 x平方+ax+b=0有一个rational根,show那个有理根实际是个整数。
Section2:
1. if d|ab, does it follow that d|a or d|b?
2.let p be the least prime factor of n, where n is composite, Prove
that if p>n的1/3次方,then n/p is prime.
3. True or false? If p and q divide n, and each is greater than
n的1/4次方,then n/pq is prime.
4 is it ture that if 2的n次方-1 is coomposite ,then n is composite? |