Réponses

2014-05-19T23:12:53+02:00
Résoudre ces équations :

2x + 14 = - 5x - 7
2x + 5x = - 7 - 14
7x = - 21
x = -21/7
x = - 3

15 - 4 (x - 3) = 3x + 2 (6 - x)
15 - 4x + 12 = 3x + 12 - 2x
- 4x - 3x + 2x = 12 - 15 - 12
- 5x = - 15
x = -15/5

3 (2x + 5) = 8 + 4x
6x + 15 = 8 + 4x
6x - 4x = 8 - 15
2x = - 7
x = - 7/2