I try to prove the next statement:
For $n>=0$ show that $5x^n - 1$ is irreducible over Q[x].
I have been doing some research and find einstein's statement but it doesn't fix the problems and the rest of the examples that I found on this page are for a very specific polynomial. I think that probably the fact of not repeated roots can help but I don't know the strategy to prove this.
Thank you in advance.