Bonjour,
enfant: p
adultes: p+3
140 enfants: 140p
130 adultes: 130 ( p+3) = 130 p + 390
a)
140p + 130p+390 = 270p + 390
b)
enfants:
15 -3 = 12
adultes :15
= 140 *12+ 130 * 15
= 1 680+ 1 950 => 3 630€
