How would you express this using mathematical symbols?

Question

"The largest common denominator of a and b is also a denominator of c."

"The largest common denominator of a and b is equal to the largest common denominator of a and c".

Answer 1

$1)$ $\gcd(a,b)|c$

$\gcd(a,b)$ means largest common denominator between $a$ and $b$;

$x|y$ means $x$ divide $y$;

$2)$ $\gcd(a,b)=\gcd(a,c)$