X 2 5x 7 )( x 2 5x 7 July 8, 2019 16 32 64 128 5x x 2 3 )+ x 2 7 5x )- 7x 2 5x x 2 3 )+ x 2 7 5x )- 7x 2 tại x =- 5 P 5x x 2 3 )+ x 2 7 5x )- 7x 2 tại x =- 5 (x ^ 2 - 5x + 7) ^ 2 - (x - 2)(x - 3) = 1
