bonjour
A = 12 x² + 16 x² + 40 x +25
A = 28 x² + 40 x +25
B = 7 x - ( 36 x² + 24 x + 4 )
B = 7 x - 36 x² - 24 x - 4
B = - 36 x² - 17 x - 4
C = - 16 x² - ( 16 x² - 1 )
C = - 16 x² - 16 x² + 1
C = - 32 x² + 1
D = 36 x² - 48 x + 16 + 4 x² - 24 x + 36
D = 40 x² - 72 x + 52