Réponses

2013-09-08T14:36:07+02:00
F = (7 - 2x)² - 4 (x + 3)²
F = [(7 - 2x) - 4 (x + 3)] [(7 - 2x) + 4 (x + 3)]
F = (7 - 2x - 4x - 12) (7 - 2x + 4x + 12)
F = (-6x - 5) (2x + 19)