a-show that (4 6) =(2) in z where (4 6) is the ideal generated by 4 and 6 and (2) is the principal ideal gerarated by 2 b- show that (6,9,15) in z Solution Notice that 4 is in (4 6) and 6 is in (4 6), so 6-4 has to be in (4 6), so 2 is in (4 6). Hence the ideal generated by 2 has to be in (4 6). This is (2) is a subset of (4 6). Also, 4 is in (2) and 6 is in (2), hence the ideal generated by 4 and 6 is in (2). this is, (4 6) is a subset of (2). Hence (2) = (4 6). Problem b is not complete. Show that (6,9,15) in z is what? Please rate :) .