hi,
I am stuck on this quesiton and any help would be appreciated.
Here is a question:
55. Let p and q be distinct primes. There is a proper subgroup J of the additive group of integers which contains exactly three elements of the set {p, p+q, pq, p^q, q^p}. Which three elements are in J?
answer: {p, pq, p^q}
thank you so much inadvance!
GR9367 Q55

 Posts: 61
 Joined: Sun Apr 04, 2010 1:08 pm
Re: GR9367 Q55
Any additive group of integers is in the form cZ (c any integer, Zthe integers). p, pq, and p^q are pmultiples while p+q and q^p are not, so the first three are in pZ, while the other two aren't.