bonjour
A = x² - 5 x + 4 x - 20
= x² - x - 20
B = 4 x² - 12 x + 9
C = x ( 7 + 9 x )
D = ( 6 x - 5 ) ( 6 x + 5 )
5 x - 3 = 2 x + 7
5 x - 2 x = 7 + 3
3 x = 10
x = 10/3
