Réponses

  • Utilisateur Brainly
2014-05-10T11:50:37+02:00
(x+1)² = 9
(x=1)²-9 = 0
(x+1-3)(x+1+3) = 0
(x-2)(x+4) = 0

x-2  =0
x =2

x+4  =0
x = 4

x²+1 = 9
x²= -1+9
x² = 8
x = V8 ou -V8  soit 2V2 ou -2V2