Réponses

2014-09-04T21:10:30+02:00

Salut,

a) A = (x + 1)(x + 3)(x + 4)

A = (x² + 3x + x + 3)(x + 4)

A = x³ + 3x² + x² + 3x + 4x² + 12x + 4x + 12

A = x³ + 5x² + 19x + 12

b) B = (x -1)(x - 5)(x - 4)

B = (x² - 5x - x + 5)(x - 4)

B = x³ - 5x² - x² + 5x - 4x² + 20x + 4x - 20

B = x³ - 10x² + 29x - 20

c) C = (2x + 1)(x - 5)(3x + 2)

C = (2x² - 10x + x - 5)(3x + 2)

C = 6x³ - 30x² + 3x² - 15x + 4x² - 20x + 2x - 10

C = 6x³ - 23x² - 33x - 10

A+