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

For which values of n≥2 does the implication:

axb=0 ⇔ a=0 or b=0

For some Zn (n should be a subscript)

NOTE: For the a x b, the x should be the x that has a circle around it. I didn't see that symbol in the "quick symbols" :)

2. Relevant equations

I know that this is true when n is a prime (answer in back of book), but I don't understand why. For example, if a=5 and b = 4, then that would also be 0 for n=5, right? Do I just not understand how to do modular arithmetic?

Thanks!

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# Homework Help: Discrete Math - Modular Arithmetic

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