Mathématiques

Question

Bonsoir svp aidez moi je dois rendre cet exo demain please please please !!
Résoudre les équations :
a. 2+(x+3)=5x
b. 6-(y+9)=y+10
c. 5+(2x+1)=4-4x
d. 2(a-1)=-5+(3a-9)
e. 1-9(b+6)=-2(4-3b)
f. -(5-x)=-6(x-1)

1 Réponse

  • a. 2+(x+3)=5x
    2 + x + 3 = 5x
    x - 5x = - 3 - 2
    - 4x = - 5
    x = 5/4
    x = 1,25

    b. 6-(y+9)=y+10
    6 - y - 9 = y + 10
    - y - y = 10 + 9 - 6
    - 2y = 13
    y = - 13/2
    y = - 6,5

    c. 5+(2x+1)=4-4x
    5 + 2x + 1 = 4 - 4x
    2x + 4x = 4 - 5 - 1
    6x = - 2
    x = - 2/6
    x = - 1/3

    d. 2(a-1)=-5+(3a-9)
    2a - 2 = - 5 + 3a - 9
    2a - 3a = - 9 - 5 + 2
    - a = - 12
    a = 12

    e. 1-9(b+6)=-2(4-3b)
    1 - 9b - 54 = - 8 + 6b
    - 9b - 6b = - 8 - 1 + 54
    - 15b = 45
    b = - 45/15
    b = - 3

    f. -(5-x)=-6(x-1)

    - 5 + x = - 6x + 6
    x + 6x = 6 + 5
    7x = 11
    x = 11/7

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