A = 4x(3x-5)
A = 4x * 3x + 4x * (-5)
A = 12x² -20x
B = (3x+5)(2x-8)
B = (3x * 2x + 3x * (-8) + 5 * 2x + 5 * (-8)
B = 6x² -24x + 10x - 40
B = 6x² -14x -40
C = 4x-5-(-3x+6)
C = 4x -5 + 3x + 6
C = 7x + 1
(je ne suis pas exactement sure de celle là :/)
D= 2x(3x-1)-(4x-2)(5x-6)
D = (6x² - 2x) - (20x² -24 -10x + 12)
D = (6x² - 2x -20x² + 24 +10x - 12)
D = -14x² +8x + 12