Question: Recall that if a prime number divides a product of two integers, then it divides one of the factors.
(a) Use this to show that as b runs though the integers from 0 to p - 1, with p prime, the products a ·p b are all different (for each fixed choice of a between 1 and p - 1).
(b) Explain why every integer greater than 0 and less than p has a unique multiplicative inverse in Zp, if p is prime.