Is 12m(3m + 21) divisible by 9? Assume the variable m represents an integer. Yes, because 12 and 9 have a common factor of 3. Yes, because 12m(3m + 21) = 9m(4(m + 7)) which is an integer because sums and products of integers are integers. Yes, because 12m(3m + 21) is a divisor of 9. No, because 12m(3m + 21) = 9m(4(m + 7)) which may not be an integer because sums and products of integers are not always integers. No, because 9 is not a divisor of 12