Mathématiques

Question

Qui peut m'aider a l'exercice 11 s'il vous plait :)
Qui peut m'aider a l'exercice 11 s'il vous plait :)

2 Réponse

  • Ex 11.

    4(x + 5) = 10x + 3
    4x + 20 = 10x + 3
    20 - 3 = 10x - 4x
    17 = 6x
    17/6 = x

    3(x - 2) = 6(x + 4)
    3x - 6 = 6x + 24
    - 6 - 24 = 6x - 3x
    - 30 = 3x
    - 30/3 = x
    - 10 = x

    7x - (5x + 3) = 5(x - 3) + 2
    7x - 5x - 3 = 5x - 15 + 2
    2x - 3 = 5x - 13
    - 3 - 13 = 5x - 2x
    - 16 = 3x
    - 16/3 = x

    7(n + 2) - 3 = 25 - (3n + 4)
    7n + 14 - 3 = 25 - 3n - 4
    7n + 3n = 25 - 4 - 14 + 3
    10n = 10
    n = 10/10
    n = 1

    4y + 3(4y - 2) = 3(y + 1)
    4y + 12y - 6 = 3y + 3
    4y + 12y - 3y = 6 + 3
    13y = 9
    y = 9/13
  • a)
    4 (x + 5) = 10x + 3
    4x + 20 = 10x + 3
    4x - 10x = 3 - 20
    - 6x = - 17
    - x = - 17/6
    x = 17/6

    b)
    3 (x - 2) = 6 (x + 4)
    3x - 6 = 6x + 24
    3x - 6x = 24 + 6
    - 3x = 30
    -x = 30/3
    -x = 10

    c)
    7x - (5x + 3) = 5 (x - 3) + 2
    7x - 5x - 3 = 5x - 15 + 2
    7x - 5x - 5x = - 15 + 2 + 3
    - 3x = - 12
    3x = 12
    x = 12/3
    x = 4

    d)
    7 (n + 2) - 3 = 25 - (3n + 4)
    7n + 14 - 3 = 25 - 3n - 4
    7n + 3n = 25 - 4 - 14 + 3
    10n = 10
    n = 10/10
    n = 1

    e)
    4y + 3 (4y - 2) = 3 (y + 1)
    4y + 12y - 6 = 3y + 3
    4y + 12y - 3y = 3 + 6
    13y = 9
    y = 9/13