27 3 x 9 4 July 8, 2019 16 32 64 128 1 9 3 x 27 4 27 mũ 3 x 9 mũ 4 x 243 (( 27 )- 2 x 9 2 3 4 27 x 9 2x 1 3 x 4 B 27 mũ 3 x 9 mũ 4 x 243 2 3 x 4 9 x 8 27 Frac 3 4 x 9 27 3 x 5 9 3 27 4 27 x 3x 9 42 6x )= 0