Greatest common divisor problem: If $\gcd(x, y) = 1$ then $\gcd(x + y, x - y) = 1$ or $2$
38295
If $\gcd (a,b) = 1$, what can be said about $\gcd (a+b,a-b)$?
19164
On the GCD of a Pair of Fermat Numbers
2208
$\gcd(a,b,c)=\gcd(\gcd(a,b),c)\,$ [GCD Associative Law]
37808
Show that $\gcd(a^2, b^2) = \gcd(a,b)^2$
60842
if $a^2+b^2=c^2$ then $gcd(a,b)=gcd(a,c)=gcd(b,c)$.
14783
A Number Theory problem (GCD)
35945
Proof that if $\gcd(a,b) = 1$ and $a\mid n$ and $b\mid n$, $ab \mid n$
82777
If $\gcd(a, b) = 1$ then prove that $\gcd(a+b, a^2-ab+b^2) = 1$ or $3$?
76126
How to find the GCD of two polynomials
65687
$\gcd(a,b)\gcd(x,y)\mid ax+by$
112031
Prove that $\gcd(2^{2^m}+1,2^{2^n}+1)=1$ if $m,n$ are positive integers.
34330
How to prove $\gcd(a^2,b^2) = (\gcd(a,b))^2$?
128199
Proving gcd(a, a+2) is 1 or 2 for every integer a?
7090
Show that $\gcd(a,bc)=1$ if and only if $\gcd(a,b)=1$ and $\gcd(a,c)=1$
127993
Let $p$ be a prime. Suppose that $\gcd(a, b) = p$. Find $\gcd(a^2,b)$ for all integers $a$ and $b$.
122096
Find $GCD(n^2+1,n+1)$
25573
If $\gcd(a,b)=1$, then $\gcd(a+b,a^2 -ab+b^2)=1$ or $3$.