Sorry to bother, this is may be simple problem, but this is sudden homework and must be presented in front of class, i'm affraid make a mistake.
1. prove that if p is prime number, and , then and
2. prove that is divisible by 2,3,5,7,13 fot any integer n
3. show that the product of three consecutive integers is divisible by 504 if the middle one is cube.
i take this from ivan niven , "introduction to number theory, fifth edition" page 57.
many thanks, i really need help.