Réponses

  • Omnes
  • Modérateur confirmé
2014-02-04T20:08:24+01:00
Salut, 4x - 7 = x +9 \\ 4x - x = 9+7 \\ 3x = 16\\ x = \frac{16}{3}
4x + 7 = x-9 ... 4x-x = -9-7... 3x = -16 ... x = -16/3