Conditions for an element to be an unit element in a ring
119067
Basic Ring Theory Question involving the unit element
73689
A question about the equivalence relation on the localization of a ring.
115920
Showing $R$ is a local ring if and only if all elements of $R$ that are not units form an ideal
133738
Can a ring without a unit element have a subring with a unit element?
111824
Sum of nilpotent and element is a unit in ring?
158873
Is every group the unit group of some ring?
105887
Ring and Subring with different Identities
116526
Finite ring has only zero divisors and units
83100
Prove that the center of a ring is a subring.
127306
Is the group of units of a finite ring cyclic?
79650
Division Rings and Division Algebras
138383
group of units in a topological ring
17059
A ring element with a left inverse but no right inverse?
81296
If A and B are ideals of a ring, show that A + B = $\{a+b|a \in A, b \in B\}$ is an ideal
138337
On a ring $R$ where $x^2 = x$, we must have that $2x = 0$ and $R$ is commutative
20613
Units (invertibles) of polynomial rings over a field
14343
Every nonzero element in a finite ring is either a unit or a zero divisor