bonjour
Exercice 1
8 a + b = 0
6 a + b = 1.6
b = - 8 a
8 a + b = 0
- 6 a - b = - 1.6
2 a = - 1.6
a = - 0.8
8 a + b = 0
- 6.4 + b = 0
b = 0 + 6.4
b = 6.4
Exercice II
a - b = 3.5
6 a + b = 0
a = 3. 5 + b
6 (3.5 + b ) + b = 0
21 + 6 b + b = 0
7 b = - 21
b = - 3
a - ( -3) = 3.5
a + 3 = 3.5
a = 3.5 - 3
a = 0.5
Exercice III
on note x le cocktail "palmier" et y "le Curtys"
5 x + 4 y = 37
3 x + 5 y = 30
- 15 x - 12 y = - 111
15 x + 25 y = 150
13 y = 39
y = 3
le curtys vaut 3 €
5 x + 12 = 37
5 x = 37 - 12
5 x = 25
x = 5
le palmier coûte 5 €
