Prove that the following ring is commutative
48537
If $\forall x \in R, x^2-x \in Z(G)$, than $R$ is commutative
30327
$\ker \phi = (x_1-a_1, ..., x_n-a_n)$ for a ring homomorphism $\phi: R[x_1, ..., x_n] \to R$
16023
Are associates unit multiples in a commutative ring with $1$?
32772
Proving units in a ring
67470
If $S$ is a ring with the property that $s=s^2$ for each $s \in S$, then is $S$ commutative?
94239
Proof that if group $G/Z(G)$ is cyclic, then $G$ is commutative
13606
Prove that $K$ is isomorphic to a subfield of the ring of $n\times n$ matrices over $F$.
50908
Showing a Ring and an Ideal are equal
137011
showing $\psi: R\to \mathbb C$ is ring isomorphism.
121750
Let $R$ be a commutative, unital ring and let $I$ be an ideal of $R.$ Prove that if $I$ is maximal then $R/I$ is a field.
92420
Characteristic of  a Non-unital Integral Ring
156878
If every commutator is idempotent, then the ring is commutative
19883
Prime ideals of the matrix ring
92962
Rings with $a^5=a$ are commutative
116000
Prove that prime ideals of a finite ring are maximal
24259
Quotient ring of $T/I$
78626
Let $R$ be a commutative ring. If $R[X]$ is a principal ideal domain, then $R$ is a field.