prove if m,n are two integers then the greatest common factor of (m,n) is divisible by every common divisor of m and n.

i get that its true by making up my own examples, but im struggling to write a proof. If somone could get me started in the right direction it would help.

from the extended euclidean algorithm there are integers x,y such that gcd(n, m) = xn + ym
and with this it should be easy to prove your question

yes silly me i was trying much more difficult methods thanks