Réponses

2013-10-10T11:59:28+02:00
2X + 2X + 2 + 2X + 4 + 3X + 9 = 131 => 9X + 15 = 131 => X = 116/9

voilà
2013-10-10T14:07:12+02:00
2xX+2x(X+1)+2x(X+2)+3x(X+3)=131
2x+2x+2+2x+4+3x+9
=131
9x=131-4-9-2
9x=116
x=116/9