Search for question
Question

1. Let m be an integer with m > 1 and let Um denote the set of congruence classes in Z/mZconsisting of elements coprime to m: U_{m}=\{x \in \mathbb{Z} / m \mathbb{Z} \mid \operatorname{gcd}(x, m)=1\} Show that Um is a group under multiplication modulo m.

Fig: 1

Fig: 2

Fig: 3