(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let U(n) be the set of all positive integers less than n and relatively prime to n. Prove that U(n) is agroup under multiplication modulo n

2. Relevant equations

3. The attempt at a solution

n [itex] | [/itex] a-a' implies n[itex] |[/itex] b(a-a') =ab-a'b

and n[itex] |[/itex]b-b' implies n[itex] |[/itex]a'(b-b') =a'b-a'b'

implies n[itex] |[/itex]ab-a'b+a'b-a'b'

=ab-a'b'

ie ab=a'b'modn

have i done enough with this?

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# Homework Help: Multiplication groups

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