Question:Let Zn = {0, 1, 2, . . . , n − 1}, let · represent...
Question
Let Zn = {0, 1, 2, . . . , n − 1}, let · represent...
Let Zn = {0, 1, 2, . . . , n − 1}, let · represent
multiplication (mod n), and let a ∈ Zn. Prove that there exists b ∈
Zn such that a · b = 1 if and only if gcd(a, n) = 1.