$a\mid b$ and $b\mid a$ but $a$ and $b$ are not associates
10908
Associated elements in a ring
116215
Prove that $P(A \cap B\mid C)=P(A \mid (B \cap C))P(B\mid C)$
58133
${a^2}{\mid}({b^3} + 1)\;$and$\;{b^2}{\mid}({a^3} + 1)$
90402
$AB$ is not invertible
4141
Prove: If $a\mid m$ and $b\mid m$ and $\gcd(a,b)=1$ then $ab\mid m$
135779
Prove the following: If $a \mid bc$, then $a \mid \gcd(a, b)c$.
139841
Proving $A\setminus(B\setminus C)$ is not equal to $(A\setminus B)\setminus C$
83475
Prove Or Disprove: tr(AB)=tr(A)*tr(B)
140167
Proving $A+A'B=A+B$ without truth tables
20823
If $\gcd(a,b) = 1$ and $a,b\mid x$ then $ab\mid x$.
115460
Proving $a\mid b^2,\,b^2\mid a^3,\,a^3\mid b^4,\ldots\implies a=b$ - why is my approach incorrect
105233
Is there a counterexample for the claim: if $A \oplus B\cong A\oplus C$ then $B\cong C$?
84626
Why in these matrices are $AB=BA$ not equal? What is the logic behind them?
147902
Prove $a \mid m$ and $b \mid m \implies \frac{a \cdot b}{\text{gcd}(a, b)} \mid m$
56512
Divisibility is transitive: $\ a\mid b\mid c\,\Rightarrow\ a\mid c$
21229
If an element is not in the set difference $A\setminus B \: \:?$
78031
$c\mid a,b\iff c\mid\gcd(a,b)$ [GCD Universal Property]