2 1 5x =- 7 July 8, 2019 16 32 64 128 2 5x 1 7 5 2 5x 1 )- 7x 2 x 1 )= 5x 7 1 2 5x 3 7 2 5x 1 2x 7 3 3x 1 2 5x 7 (- 4x 2 6x 1 )+( 5x 7 2 5x 7 )( 1 x )= 0 2 4x 1 )= 2 5x 7 2 7x 1 5x 3 3 2 x 1 5x 7 12x 1 2 6 5x )+ 7 5x 3x 2 1 7x 3 49 5x 2 =( 1 7 11 x 7x 2 5x 1 0