Bonjour,
Total = 1 450€
On pose :
a = 1ere pers.
b = 2eme pers.
c = 3eme pers.
a = 150+b ==> b = a-150
a = c-250 ==> c = a+250
a+b+c = 1 450
a+ (a-150) + (a+250) = 1 450
3a + 100 = 1 450
3a = 1350
a = 1 350/3
a = 450€
b = a-150 = 450-150 = 300€
c = a+250 = 450+250 = 700€
Vérification :
450+300+700 = 1 450€