A question about Rings (invertible)
14873
$1+a$ and $1-a$ in a ring are invertible if $a$ is nilpotent
20613
Units (invertibles) of polynomial rings over a field
88307
Commutative property of ring addition
8787
In a ring $(A,+, \cdot)$ if $aba = a$ then $bab = b$ and all non zero elements in $A$ are invertible.
111104
Ring theory notation question
30327
$\ker \phi = (x_1-a_1, ..., x_n-a_n)$ for a ring homomorphism $\phi: R[x_1, ..., x_n] \to R$
98818
Quotient ring of a localization of a ring
94378
Is Linear transformations $T_1,T_2 : \mathbb{R}^n\rightarrow \mathbb{R}^n$ Invertible?
32772
Proving units in a ring
87382
Non-invertible elements form an ideal
28327
(Simple) Examples on Non-Commutative Rings
32108
$ a\in \Bbb Z_n$ is invertible $\,\Rightarrow\gcd (a,n) =1$
17059
A ring element with a left inverse but no right inverse?
5594
Question about the Euclidean ring definition
22604
Can $R \times R$ be isomorphic to $R$ as rings?
152013
elementary ring proof with composition of functions and addition of functions as operations
39755
In a faithfully flat ring extension, is $\operatorname{ht}I=\operatorname{ht}IS$ right?