How is HCF (c, d) = HCF (d, r), where c = dq +r (by Euclid's division lemma)?
190
Why $\gcd(qb+r,b)=\gcd(b,r)$?
77361
How to prove $|H|[K:K \cap (g^{-1}Hg)]=|K|[H:H \cap (gKg^{-1})]$?
141643
Showing $\rho (x,y)=\frac{d(x,y)}{1+d(x,y)}$ is a metric
157508
prove $lcm(a,gcd(b,c))=gcd(lcm(a,b),lcm(a,c))$
11600
$\gcd(a,\operatorname{lcm}(b,c))=\operatorname{lcm}(\gcd(a,b),\gcd(a,c))$
41295
Divisibility, LCM and GCD for fractions (rationals)
25174
Solve for $A,B$: $\mathrm{LCM}(A,B)=168$, $\mathrm{HCF(A,B)}=12$
236
Proof of general Euclid's Lemma in a UFD (by Euclidean algorithm?)
67660
Prove $\,b\equiv c\pmod{\!m}\Rightarrow \gcd(b,m)=\gcd(c,m)$ i.e. $\gcd(c+km,m) = \gcd(c,m)$
28021
Showing that these two definitions of $\gcd(a,b)$ are equivalent
104124
Prove or disprove: $A-(B-C) = (A-B)-C$
106416
If $n,m \in \mathbb{N}$ then there are $c,d$ such that $cd = (m,n)$, $(c,d) = 1$ and $(m/c,n/d) = 1$.
137608
Proof of Euclid's formula for primitive Pythagorean Triples
142693
$\gcd(a,b) = \gcd(a + b, \mathrm{lcm}[a,b])$
62879
Question about the proof of $GCH$ holds in $\mathbf L$
62755
The simplest way of proving that $|\mathcal{P}(\mathbb{N})| = |\mathbb{R}| = c$
139833
Prove that $\gcd(M, N)\times \mbox{lcm}(M, N) = M \times N$.