3 x 2 4x 5 1 9 July 8, 2019 16 32 64 128 3 mũ x2 4x 5 1 9 4x 5 2 2x 3 )( x 1 )= 9 3 x 2 )- 5 4x =- 5x 3 2x 1 )+ 9x 3 3x 1 )- 5 4x 2 )+ 9 2 x )= 15 3 x-5=x+3
