Svp aidez moi je n'y comprend rien ...

B = (6x-7)(3x-2)
B = 18x²-12x-21x+14
B = 18x²-33x+14

2)
x = 0
B = 0-0+14 = 14
x = 1
B = 18-33+14
B = 32-33
B = -1

(6x - 7 ) (3-2x) = 18x - 21 -12x² +14x = 
Pour x= 0:
(6x - 7 ) (3-2x) = -21
-12x² +32x -21 = -21

Pour x=1
(6x - 7 ) (3-2x) = (6-7)(3-2) = (-1) * 1 = -1
-12x² +32x -21= -12 + 32 - 21 = -1