Ring with unity. Show that if ab units, then a and b are units.
32772
Proving units in a ring
63535
Prove that if $A – C = B – C$ and $A\cap C = B\cap C$ then $A = B$
17032
If $ab=ba$, Prove $a^2$ commutes with $b^2$
2208
$\gcd(a,b,c)=\gcd(\gcd(a,b),c)\,$ [GCD Associative Law]
18800
If A and B are symmetric is AB=BA true?
94516
If $3$ divides $a^2 + b^2$, then $3$ divides $a$ and $3$ divides $b$
158308
Proving that if $a,b$ are even, then $\gcd(a,b) = 2 \gcd(a/2, b/2)$
24845
Let $a\mid c$ and $b\mid c$ such that $\gcd(a,b)=1$, Show that $ab\mid c$
99715
Proper ideal and units proof
123555
Proving that if $ab=e$ then $ba=e$
145719
Similarity between $A$ and $B (2\times 2)$.
50908
Showing a Ring and an Ideal are equal
13162
Prove $\alpha \in R[[x]]$ is a unit iff $a_0 \in R$ is a unit
60707
Show that if $ \ A \cup B = A$ and $ \ A\cap B = A$ then $ \ A = B$
155545
Showing that $a \mid b$ and $b \mid a$ if and only if $a= \pm b$.
86807
The units of $\mathbb Z[\sqrt{2}]$
139934
In $\mathbb{Z}/(n)$, does $(a) = (b)$ imply that $a$ and $b$ are associates?