Respuesta :
Prime factorization of 15 is 3·5
Prime factorization of 28 is 2·2·7
As you can see 15 and 28 have no common factor so greatest common factor would be 1.
Prime factorization of 28 is 2·2·7
As you can see 15 and 28 have no common factor so greatest common factor would be 1.