Mathématiques

Question

Aider moi svp les gens merci !!
Aider moi svp les gens merci !!

1 Réponse

  • 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 €