9 5x 7 5x 4 July 8, 2019 16 32 64 128 5x 9 4 5x 7 4 1 3 5x 9 4 7 5x 7 5x 4 6x 5x 9 6 5x 7 2 9 2 4 5x 9x + 7 = - 5x - 7