Bonsoir,
A = a(2a + 4) = 2a² + 4a
B = a(-5a + 3) = -5a + 3a
C = 7a(2a - 5) = 14a² - 35a
D = -a(4a - 7) = -4a² + 7a
E = a(3a - 4) + a(5a - 3) = 3a² - 4a + 5a² - 3a = 8a² - 7a
F = (a - 5)(a - 7) = a² - 7a - 5a + 35 = a² - 12a + 35
G = (2a - 5)(4a - 7) = 9a² - 14a - 20a + 35 = 9a² - 34a + 35
H = (2a - 5)(4a - 7) + (a - 3)(6a - 7) = 9a² - 34a + 35 + 6a² - 7a - 18a + 21 = 15a² - 59a + 56
