Réponses

2013-12-21T23:44:11+01:00
N + 40 = 2(14 + n)
n + 40 = 28 + 2n
        n = 2n + 28 - 40
        n = 2n - 12
 n - 2n = - 12
 n - 2n = - 12
      - n = - 12
        n = 12.
2013-12-21T23:57:47+01:00