Bonjour
Factoriser :
B = (2x - 3)(5x - 7) - (2x - 3)^2
B = (2x - 3)(5x - 7 - 2x + 3)
B = (2x - 3)(3x - 4)
b) résoudre :
(2x - 3)(3x - 4) = 0
2x - 3 = 0 ou 3x - 4 = 0
2x = 3 ou 3x = 4
x = 3/2 ou x = 4/3
c) B pour x = -1/2
B = (2 * (-1/2) - 3)(3 * (-1/2) - 4)
B = (-1 - 3)(-3/2 - 4)
B = (-4)(-3/2 - 8/2)
B = (-4) * (-11/2)
B = 22