number theory - Prove that for any $m > 0$, $gcd(mb,mc) = mgcd(b,c)$.

Property of GCD

For any $m > 0$ , $\gcd(mb,mc) = m\gcd(b,c)$.

Please prove this. I am learning the Theory Of Numbers in Detail but I am not able to find the proof for this. It is not available in the internet also. So please help me with this problem. Please prove this without using the Euclidean Algorithm as it is deriver from this.