Page "Greatest common divisor" Paragraph 64

* The gcd is a multiplicative function in the following sense: if a < sub > 1 </ sub > and a < sub > 2 </ sub > are relatively prime, then gcd ( a < sub > 1 </ sub >· a < sub > 2 </ sub >, b ) = gcd ( a < sub > 1 </ sub >, b )· gcd ( a < sub > 2 </ sub >, b ).