This thread is a repost. Sorry. Marking it as solved and requesting that it be removed please
RTP: If , then , where a,b are positive integers
This is impossible, so our assumption is wrong
Thus our statement is true
1. Is this proof valid?
2. Can I generalize to :If gcd(a,b)=k, then gcd(a, (a+b))=k
3. Is there a simpler non-contradiction, non-FTA proof?