Bonsoir,
A = (2x + 5)(4x + 8)
A = 2x * 4x + 2x * 8 + 5 * 4x + 5 * 8 #Distributivité double.
A = 8x² + 16x + 20x + 40
A = 8x² + 36x + 40
B = -3(-7 + 4x)
B = (-3) * (-7) + (-3) * 4x #Distributivité simple.
B = -12x + 21
C = 2(3x - 5) + (2x² - 6x + 4) - (3x² + 4x - 7)
C = 2 * 3x - 2 * 5 + 2x² - 6x + 4 - 3x² - 4x + 7
C = 6x - 10 -x² - 10x + 11
C = -x² - 4x + 1
Bonne soirée,
Thomas
