bonsoir
a = - 3 x² + 27 x + 4 x - 36 + 21 x² - 28 x + 6 x - 8
a = 18 x² + 9 x - 44
b = 12 x + 20 - 3 x² - 5 x + 4 x + 8 - x² - 2 x
b = - 4 x² +9 x + 28
c = 16 x² - 8 x + 1 - ( 4 x² - x - 24 x - 6)
c = 16 x² - 8 x + 1 - 4 x² + x + 24 x + 6
c = 12 x² + 17 x + 7
d = 3 ( 2 x² + x - 10 x - 5) + (12 x² + 6 x - 14 x - 7)
d = 6 x² + 3 x - 30 x - 15 + 12 x² + 6 x - 14 x - 7
d = 18 x² - 35 x - 22