# Thread: modular arithmetic proof

1. ## modular arithmetic proof

let n=pq where p,q are distinct positive odd prime numbers.let [a] be a fixed non zero element in Zn. How many distinct solutions are there in Zn to the equation: [a][x]=[1]?

2. Originally Posted by Deepu
let n=pq where p,q are distinct positive odd prime numbers.let [a] be a fixed non zero element in Zn. How many distinct solutions are there in Zn to the equation: [a][x]=[1]?

Either none or exactly one. Think of this, try to work out a proof and, after this, if you're stuck somewhere then write back.

Tonio