A= (-2x-5)(6x+3) - (-8x-4)(-2x-5)
On utilise la double distributivité
A = -2x*6x -2x*3 -5*6x -5*3 - ( -8x*-2x -8x*-5 -4*-2x -4*-5 )
A = -12x² -6x -30x -15 - (16x² + 40x + 8x + 20)
A = -12x² -6x -30x -15 - 16x² - 40x - 8x - 20
A = -12x² -16x² -6x -30x -40x -8x -15 -20
A = - 28x² - 84x - 35
