Je bloque vous pourrai m'aider ex 60 merci

bonsoir

a) Zoé = x et Anna = 3 x
x + 3 x = 56.40
4 x = 56.40
x = 14.10
Zoé = 14.10 et Anna = 42.30

b) Zoé = x et Anna = x/2
x + 0.5 x = 56.40
1.5 x = 56.40
x = 37.60
Zoé = 37.60 et Anna = 18.80 €

c) Zoé = x et Anna = x + 5
x + x +5 = 56.40
2 x = 56.40 - 5
2 x = 51.40
x = 25.70
Zoé = 25.70 et Anna 20.70

d) Zoé = x et Anna = x - 4
x + x - 4 = 56.40
2 x = 56.40 - 4
2 x = 52.40
x = 26.20
je te la laisse calculer