Hello all. I came across this question which is "prove that (5^125-1)/(5^25-1) is composite". I am not even getting a clue as to how I can attack this problem. Any help would be greatly appreciated. Please note that we need to prove (5^125-1)/(5^25-1)=1+5^25+5^50+5^75+5^100 as composite and not 5^125-1.