7 5 4 5 9 July 8, 2019 16 32 64 128 7 5 5 4 9 2 7 4x 5 )- 4 6x 5 )=- 91 7 5 4 9 6 5 7 4 5 x 9 7 7 5 9 1 4 5 3 4 7 5 5 9 5 4 5 9 ⋅ 3 7 4 5 5 7 and 9 11 X 5 6 5 7 4 9