4 7 x 21 1 July 8, 2019 16 32 64 128 4 7 x 21 16 2 3 4 7 x 11 21 4 21 x 7 12 4 7 x 10 21 9 4 x 7 21 16 y 43 4 7 x 4 7 x 21 2 10 7 x 2 )= 4 x 1 )- 21 14 21 7 4 x 2 1 4 x 22 7 x 21 2 7 x 7 16 21 4 4 7 x 4 7 x 21 2 divided by 10 21 4 x 7 5 7 5 1 2 7 x 8 (- 14 (- 4 )) (- 21