Respuesta :
					                   The greatest common factor is sometimes one because that is the only thing that can go into it.
					                
					                
					             
					                   Its because one of the numbers can be prime numbers, the 
greatest common factor of 12 and 13 it's 1 because 13 it's a prime 
number or because they don't have common prime factors.Prime numbers are
 the numbers who can be divided just by 1 and themselves.
					                
					                
					             