Bonjour aider pour cette exo merci d'avance

Bonsoir

1) Developper :

H = (4x - 1)(5x - 3) - (4x - 1)^2

H = 20x^2 - 12x - 5x + 3 - (16x^2 - 8x + 1)

H = 20x^2 - 16x^2 - 17x + 8x + 3 - 1

H = 4x^2 - 9x + 2

2) factoriser :

H = (4x - 1)(5x - 3 - 4x + 1)

H = (4x - 1)(x - 2)

3) calculer H pour x = 1/2 :

H = (4 * 1/2 - 1)(1/2 - 2)

H = (2 - 1)(1/2 - 4/2)

H = 1 * (-3/2)

H = (-3/2)

4) résoudre : (4x - 1)(x - 2) = 0

4x - 1 = 0 ou x - 2 = 0

4x = 1 ou x = 2

x = 1/4 ou x = 2