Répondre :
Réponse :
Explications étape par étape :
1)
cartes (Assia) = x
x = 2* cartes(Karim) ⇔ cartes(Karim) = x/2
x = cartes (Leo) + 20 ⇔ cartes(Leo ) = x - 20
En résumé :
cartes (Assia) = x
cartes(Karim) = x/2
cartes(Leo ) = x - 20
cartes (total) = x + x/2 + x-20
= 2x + x/2 -20
= 4x/2 + x/2 -20
cartes (total) = 5x/2 - 20
2)
cartes(total) = 260 ⇔
5x/2 - 20 = 260
5x/2 = 260+20
5x/2 = 280
5x = 280*2
5x= 560
x= 560/5
x = 112
3)
cartes (Assia) = x = 112
cartes(Karim) = x/2 = 56
cartes(Leo ) = x - 20 = 92
bonjour
Assia = x
Karim = x /2
Léo = x - 20
x + x /2 + x - 20 = 260
x + 0.5 x + x - 20 = 260
2.5 x = 260 + 20
2.5 x = 280
x = 112
Assia en a 112
Karim = 112 : 2 = 56
Léo = 112 - 20 = 92