10 9 7 4x2 5 July 8, 2019 16 32 64 128 10 9 7 4 x 2 5 1 4 5 x 2 2 7 x 10 9 10 ^ 9 + 7 10 - 2 4/9 10- 5 4/9 10 7 x 10 7