Réponses

  • Utilisateur Brainly
2013-09-02T07:30:16+02:00
A) (2x+3)²=36
2x+3=6 ou 2x+3=-6
x=3/2 ou x=-9/2

b) 5x²-7x=0
x(5x-7)=0
x=0 ou x=7/5

c) 4x²-9-2(2x-3)+x(2x-3)=0
(2x-3)(2x+3)-2(2x-3)+x(2x-3)=0
(2x-3)(2x+3-2+x)=0
(2x-3)(3x+1)=0
2x-3=0 ou 3x+1=0
x=3/2 ou x=-1/3

d) (2x-3)(x²+1)=0
2x-3=0 car x²+1>0
x=3/2

e) 1/x=0
pas de solution

f) 1/(x-1)=2
x-1=1/2
x=3/2

g) (2x-3)/(x+1)=3/4
(2x-3)/(x+1)-(3x+3)/(4x+4)=0
(8x-12-3x-3)/(4x+4)=0
(5x-15)/(4x+4)=0
(x-3)/(x+1)=0
x=3