If (a, b) = d, then (a/d, b/d) = 1
49109
Proving $\gcd \left(\frac{a}{\gcd (a,b)},\frac{b}{\gcd (a,b)}\right)=1$
43376
If $A$ is compact and $B$ is closed, show $d(A,B)$ is achieved
113211
Arithmetics of cardinalities: if $|A|=|C|$ and $|B|=|D|$ then $|A\times B|=|D\times C|$
90480
Code for (a,b) with gcd(a,b)=1?
80684
Counter example for $(A \times B) \cap (C \times D) = (A \cap C ) \times (B \cap D)$
31465
Prove that if $a \mid b$ then $\gcd(a,b) = |a|$
91980
Prove that f is one-to-one on D
34362
Are there any examples of $\frac{a}{b}+\frac{c}{d}=\frac{a+c}{b+d}$?
124742
P(A|C)=P(A|B)*P(B|C)?
120736
If xy + yz + zx = 1, ...........
33633
Re:$ (a,b,c,d)=(pr+qs, qr-ps,pr-qs,ps+qr) $
126280
In a P.I.D., if $a^m = b^m$ and $a^n = b^n$ for $m, n \in \mathbb{N}$ with $\gcd(m,n) = 1$, then $a=b$
33542
When is $A- B = B- A$?
20823
If $\gcd(a,b) = 1$ and $a,b\mid x$ then $ab\mid x$.
76764
Find two closed subsets or real numbers such that $d(A,B)=0$ but $A\cap B=\varnothing$
66563
Is $ (A∪B)×(C∩D)=(A∪C)×(B∪D)$ true for all sets A,B,C and D?
85076
Is it true that $d(x,Y)=d(x,y_0)$ for some $y_0 \in Y$ when $Y$ is closed?