16.9 a) Show that an element a E(Z,,, O) is a unit iff (a,n) = 1.
To show that an element
1. If
2. If
Let's proceeding with the proof:
1. If
If
By definition of the operation
Now, let's applying the Euclidean algorithm to find the greatest common divisor of
By definition,
Since
The only positive integer that divides
Step by step
Solved in 3 steps
