bonjour
A = 3 x + 24 + 28 x + 8
= 31 x + 32
B = 5 x - 5 - 14 x - 21 x²
= - 21 x² - 9 x - 5
C = 8 x - 10 x² - x + 7
= - 10 x² + 7 x + 7
D = 3 - 8 x - 20 x + 35
= - 28 x + 38
E = 21 - 14 x - 8 x² + 4 x
= - 8 x² - 10 x + 21
F = 7 x - 10 + 45 x + 63 x - 7
= 115 x - 17