Réponses

  • Utilisateur Brainly
2014-06-02T12:11:16+02:00
(2x+3)²-1=0

= a²-b² qu'on facto (a-b)(a+b) = 0

(2x+3-1)(2x+3+1) = 0
(2x+2)(2x+4) = 0

2x+2 = 0
2x = -2
x =-1

2x+4 = 0
2x =-4
x = -2

on pouvait facto encore plus :

(2x+3-1)(2x+3+1) = 0
(2x+2)(2x+4) = 0
4(x+1)(x+2) = 0

x+1 = 0
x =-1

x+2 = 0
x =-2