Réponses

2014-01-18T18:18:29+01:00
Bonsoir

stylo = x
cahier = x + 0.30
copie = 2(x +0.30) = 2x +0.60
elle achète
3x + 5(x +0.30) + 2( 2x +0.6)
stylo = 1 €
cahier = 1 + 0.3 = 1.3
copie = 2 x 1.3 = 2.6
montant des achats = 3 + (5 x 1.3) + (2 x 2.6)
3 + 6.5 + 5.2 = 14.7 €