Réponses

2013-05-26T16:41:14+02:00
2013-05-26T16:42:53+02:00

7x+2=3x+12

7x+2-3x=3x+12-3x

4x+2=12

4x=10

x=10/4

x=5/2

 

Donc :

 

x=2,5