Bonjour,
A = 3(-7x - 3) = -21x - 9
B = -4(7 - 9x) = -28 + 36x
C = 10(4 - x) = 40 - 10x
D = (3x - 4)(7x + 5)
D = 21x² + 15x - 28x - 20
D = 21x² - 13x - 20
E = (8x - 1)(5x - 7)
E = 40x² - 56x - 5x + 7
E = 40x² - 61x + 7
F = (x + 6)(5 + x)
F = 5x + x² + 30 + 6x
F = x² +11x + 30
Comme tu l'as écrit :
F = x + 6(5 + x)
F = x + 30 + 6x
F = 7x + 30
Bonne journée !
