X 1 2 3x 1 3 3x 1 6 9 July 8, 2019 16 32 64 128 1 3 x − 1 + 9 x + 1 2 − 3 x + 3 + 3 3 x − 9 ≥ 3 x + 1 3 x 3 x 3 x 3 x
