# Finite ring proofs

Please see the attached pdf. I need a detailed, rigorous proof of this with explanation of the steps so I can learn.

Let R be a finite ring.

a. Prove that there are positive integers m and n with m>n such that x^m for ever x E R.

b. Give a direct proof (i.e. without appealing to part c) that if R is an integral domain, then it is a field

c. Suppose that R has identity, prove that if x E R is not a zero divisor, then it is a unit

https://brainmass.com/math/ring-theory/finite-ring-proofs-241298

#### Solution Preview

Proof:

(a) Since R is finite, assume |R| = n, then for any non-zero element x in R, we have x^n = x.

Now let m = n^2 > n, then x^m = x^(n^2) = (x^n)^n = x^n

For x = 0, we always have x^m = x^n = 0.

Therefore, we find m>n, such that for all x in R, x^m = x^n.

(b) For each nonzero element a in R, ...

#### Solution Summary

This solution provides a series of proofs regarding a finite ring and positive integers, integral domain, and zero divisor.