15 7x x 1 3 July 8, 2019 16 32 64 128 4 7x 15 1 x 3 4 2x 1 5 15 3 x 2 )=- 7x 2 x 1 7x 15 3 x 12 )+ 4 x 1 15 x - 7 7x 15