Help me answer this Number Theory question on GCD (involves exponents)
6012
Prove that $\gcd(a^n - 1, a^m - 1) = a^{\gcd(n, m)} - 1$
7090
Show that $\gcd(a,bc)=1$ if and only if $\gcd(a,b)=1$ and $\gcd(a,c)=1$
147317
multiple choice question on number theory
19500
How can I find $\gcd(a^m+1,a^n+1)$ with $a,m,n$ positive integers?
117098
Properties of the greatest common divisor: $\gcd(a, b) = \gcd(a, b-a)$ and $\gcd(a, b) = \gcd(a, b \text{ mod } a)$
97469
How to prove $|a^k|=n/\gcd(n,k)$ whenever $|a|=n$?
87846
If $\gcd (x,4) = 2$ and $\gcd(y,4) = 2$ then $\gcd(x+y,4) = 4$
62959
How to find GCD, LCM on a set of numbers
5708
Prove that if $k\ge 1\,$ and $\,a^k\equiv 1\pmod{\! n}$ then $\gcd(a,n)=1$
150185
Let $d=GCD(n^2+5,n^3-5n^2+6n)$ show that $d|630$
80148
Prove $\gcd(a+b,a^2+b^2)$ is $1$ or $2$ if $\gcd(a,b) = 1$
126358
Prove for $\gcd$ of two integers $a,b$, that $(a^n,b^n) = (a,b)^n$
128199
Proving gcd(a, a+2) is 1 or 2 for every integer a?
95533
I need some help with a GCD and LCM's Problem
113641
Suppose the gcd (a,b) = 1 and c divides a + b. Prove that gcd (a,c) = 1 = gcd (b,c)
91506
If $\gcd(a,b) = 1$ then $\gcd(a,a + b) = 1$
59006
Proof of $\gcd(n!+1, (n+1)!+1)=1$?