Bonsoir,

Exercice 1 :

A = 5x² - 3x + 1 - 8x²- 2

A = - 3x² - 3x - 1

B = x - 4x² + 7 + 3x² + x - 12

B = -x² + 2x - 5

Exercice 2 :

A = 5 (2x - 7)

A = 10x - 35

B = (5 + 2x) X 3

B = 15 + 6x

C = -x (3x + 7)

C = -3x² - 7x

D = - 4x (2x - 6)

D = - 8x² + 24x