kbowers10 kbowers10 14-10-2020 Mathematics contestada I know i already asked this but i need the answer!!!! Which expression shows the sum 9 + 21 rewritten as a product of the GCF and a sum? O 9(1 + 21) O 3(3 + 7) O 3(3 + 21) O 9(1 + 3)