bjr

* = multiplié par...

distributivité : k( a+b) = k*a + kb

donc :

A = -2 (4a - 5) = -2 * 4a - 2 * (-5) = -8a + 10

B = 3a (-a + 7) = 3a * (a) + 3a * 7 = -3a² + 21a

C = x (3x + 2) = x * 3x + x * 2 = 3x² + 2x

D = -3 (2x - 5) = -3 * 2x - 3 * x (-5) = -6x + 15

allez tu continues