Regarding greatest common divisors.
190
Why $\gcd(qb+r,b)=\gcd(b,r)$?
117777
What are the zero divisors of $C[0,1]$?
157508
prove $lcm(a,gcd(b,c))=gcd(lcm(a,b),lcm(a,c))$
154959
Proof of associativity of GCD?
78852
If $\gcd(m,n) =1, $ then $m\mathbb{Z}/ mn\mathbb{Z} \cong \mathbb{Z}/(n)$
32344
Let $a,k,m$ be integers. Prove that $\gcd(ka,km) = k\gcd(a,m)$.
41926
Why do we say "lowest common denominator" when we mean "greatest common divisor"?
151434
If integers $a$ and $b$ are not both zero, then $\gcd(a,b)=\gcd(a-b,b)$
27449
Product of Divisors of some $n$ proof
134739
product of divisors of n as a power of n.
48452
Proof that $\gcd$ divides $\operatorname{lcm}$
83871
GCDs in integral domains are unique up to unit factors (associates)
37960
Zero Divisors in Direct Product of Rings
96376
Why do we notate the greatest common divisor of $a$ and $b$ as $(a,b)$?
152506
The greatest common divisor is the smallest positive linear combination
25891
GCD in polynomial rings with coefficients in a field extension
105832
prove that if $\gcd(a,b)=1$ then $\gcd(a^2, b^2)=1$