Réponses

2014-10-28T17:16:43+01:00
Bonjour

a) 6 - 21 x = 4 - 2 x -1
    - 21 x + 2 x = - 1 + 4 - 6
    - 19 x = - 3
    x = 3/19

b) 6 x - 3 - x - 7 = 0
     5 x = 7 +3
    5 x = 10
      x = 2

c) 4 + 2 x + 1/2 = x /4 - 1/2
    16 + 8 x + 2 = x - 2
  8 x - x = - 2 - 16
  7 x = - 18
x = - 18/7 

d) 9 - 2 x + 7/3 =  4 x /6  -1/3
    54 - 12 x + 14 = 4 x - 2
   -12 x - 4 x = - 2 - 54 -14
  - 16 x = - 70 
     x = 70/16
 x = 35/8