Réponses

2014-05-28T14:40:58+02:00
(x+1)/y = 1/3
x/(y+1) = 1/4

3(x+1) = y
4x = y+1

3x+3 = y
4x -1 = y

on a alors :
3x+3 = 4x-1
4x-3x = 3+1
x = 4             et  y = 3x4+3 = 12+3 = 15

vérification :
4x4-1 = 15
16-1 = 15
15 = 15  OK