4 6 x 90 July 8, 2019 16 32 64 128 6 4 9031 x 4 x 6 2 900 20 4 2 x 6 90 20 4 mũ 2 x 6 90 900 x 4 6 4 x 4 5x 6 90 90 x 4 5 4 × 90 4 x 90 6 x 90 90 x 4 =
