3 7 x 21 July 8, 2019 16 32 64 128 3 7 x 21 1 3 7 x 21 9 3 7 x 21 4 3 7 x 21 6 3 7 x 21 5 3 7 x 21 8 3 7 x 21 30 3 7 x 21 72 3 7 x 210 3 7 x 21 15 3 7 х 21 3 x 7 )=- 21 3x 3 7 x 14 21 3 7 x 2 21 3 7 х 8 21
