81 x 9 2 2 July 8, 2019 16 32 64 128 9 * 81 x 1 27 x 2 1 81 (- x 9 2x =( 27 3x 2 9 81 x 27 2 x 9 2x 1 81 x 2 3x 9 2x 1 81 x 2 81 x 6 mũ 2 9 mũ 2 x 64 2 1 9 x 2 81 81+ x 11
