Proof of associativity of GCD?
2208
$\gcd(a,b,c)=\gcd(\gcd(a,b),c)\,$ [GCD Associative Law]
63965
How can I compute the sum of $ {m\over\gcd(m,n)}$?
117098
Properties of the greatest common divisor: $\gcd(a, b) = \gcd(a, b-a)$ and $\gcd(a, b) = \gcd(a, b \text{ mod } a)$
36
Prove: If $\gcd(a,b,c)=1$ then there exists $z$ such that $\gcd(az+b,c) = 1$
23590
Show that $\gcd\left(\frac{a^n-b^n}{a-b},a-b\right)=\gcd(n d^{n-1},a-b)$
97469
How to prove $|a^k|=n/\gcd(n,k)$ whenever $|a|=n$?
77278
If $\,\gcd(a,b) = {\rm lcm}(a,b)\,$ then prove $a=b$
69967
How to prove $\gcd(a^m-b^m,a^n-b^n) = a^{\gcd(m,n)} - b^{\gcd(m,n)} $?
28021
Showing that these two definitions of $\gcd(a,b)$ are equivalent
66748
Show that if $a \equiv b \pmod n$, $\gcd(a,n)=\gcd(b,n)$
153128
Proof of associativity of convolution
18817
Does commutativity imply Associativity?
21788
Proving that if $ad-bc = \pm 1$, then $\gcd(x,y) = \gcd(ax +by, cx + dy)$
137369
Inductive proof of gcd Bezout identity (from Apostol: Math, Analysis 2ed)
82777
If $\gcd(a, b) = 1$ then prove that $\gcd(a+b, a^2-ab+b^2) = 1$ or $3$?
7091
If $\gcd(a,b)=1$, then $\gcd(a^n,b^n)=1$
121156
Prove that: $\gcd[a,b,c]=\frac{abc.\operatorname{lcm}(a,b,c)}{\operatorname{lcm}(a,b)\operatorname{lcm}(a,c)\operatorname{lcm}(b,c)}$