Invertible elements in a commutative ring
69151
Two definitions of Jacobson Radical
7034
Prove that $A+I$ is invertible if $A$ is nilpotent
10908
Associated elements in a ring
72230
Equivalence of definitions of prime ideal in commutative ring
88307
Commutative property of ring addition
18585
Showing $A-I$ is invertible, when $A$ is a skew-symmetric matrix
7303
How many idempotent elements does the ring ${\bf Z}_n$ contain?
79650
Division Rings and Division Algebras
126331
Associative ring with identity, inverses, divisors of zero and Artinianity
28327
(Simple) Examples on Non-Commutative Rings
77198
Showing that the characteristic of a commutative ring R without zero divisors is 0 or prime
82609
Ring such that $x^4=x$ for all $x$ is commutative
63192
A chain ring with Krull dimension greater than one
119297
Finding invertible polynomials in polynomial ring $\mathbb{Z}_{n}[x]$
110984
Ideals and prime ideals in a commutative ring.
18971
Show that a ring is commutative if it has the property that ab = ca implies b = c when $a\neq 0$
119052
Finding invertible elements in $\mathbb{Z}/m\mathbb{Z}$