Réponses

  • Utilisateur Brainly
2014-10-26T17:01:17+01:00
X - 7 = 4
x = 4 + 7
x = 11

2x = 13
x = 13/2

9 - x = 5
9 - 5 = x
4 = x

4/x = 9/5
20 = 9x
20/9 = x
Meilleure réponse !
2014-10-26T17:03:54+01:00
1)
 x - 7 =  4
x = 4 + 7
x = 11
 
2)
2x = 13
x = 13/2
x = 6,5

3)
9 - x = 5
-x = 5 - 9
- x = - 4
x = 4

4)
4/x= 9/5

20/5x = 9/5
20x = 9
x = 20/9