Bonsoir quelqu’un pourrait m’aider merci d’avance Pour l’exercice 14

Bonsoir,

a) (x + 6)(5 + x)

= x * 5 + x * x + 6 * 5 + 6 * x

= 5x + x² + 30 + 6x

= x² + 6x + 5x + 30

= x² + 11x + 30

b) (4x - 5)(x + 3)

= 4x * x + 4x * 3 - 5 * x - 5 * 3
= 4x² + 12x - 5x - 15

= 4x² + 7x - 15

c) (4 + x)(x - 5)

= 4 * x - 5 * 4 + x * x - 5 * x

= 4x - 20 + x² - 5x

= x² + 4x - 5x - 20

= x² - x - 20

d) (2x - 7)(2x - 1)

= 2x * 2x - 1 * 2x - 7 * 2x - 7 * (-1)

= 4x² - 2x - 14x + 7

= 4x² - 16x + 7