Réponses

2014-05-08T16:51:26+02:00
A) 3x+2=x-10
3x -x = -10 -2
2x = -12
x =-12/2
x =  -6

 b) 2x-5=5x+1
2x -5x = 1 +5
-3x = 6
x = 6/-3
x =  -2

c) (x-5)(x+8)=0

x-5 = 0          x+8 =0
x = 5              x = -8

d) 5x(4-x)=0 

5x =0    4-x = 0
x = 0     -x = -4
x =0   et  x = 4


e) (2x+1)²=0 
(2x+1) (2x+1) = 0

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