7 9 х 3 21 July 8, 2019 16 32 64 128 7 9 x 3 21 7 9 3 21 7 9 х 3 4 х 5 21 216 х 9 3 50 7 3 9 (- 7 х )= 0 9 9х 21 7 9 x 3 21 simplified 7 - 9 9 2-3 7 9 3/7 х 5/22
