Réponses

2014-09-12T21:19:18+02:00
Bonsoir

H = (5b +3)² - (5b -3)² 
H = (5b +3 - 5b +3)(5b +3 + 5b -3)
H = 6 (10b)

L = 9b² - 25
L = (3b -5)(3b +5)