Mathématiques

Question

Résoudre les équations d inconnues x suivantes: a) 4x+11 = 2x+15 b) 3x+2 = 2x-5 c) 5x-3 = x-5 d) 7x+5 = -3x+2

2 Réponse

  • 4x + 11 = 2x + 15
    4x - 2x = 15 - 11
    2x = 4
    x = 4/2
    x = 2
    ==================
    3x + 2 = 2x - 5
    3x - 2x = - 5 - 2
    x = - 7
    ==================
    5x - 3 = x - 5
    5x - x = - 5 + 3
    4x = - 2
    x = - 2/4
    x = - 1/2
    ==================
    7x + 5 = - 3x + 2
    7x + 3x = 2 - 5
    10x = - 3
    x = - 3/10

  • a/
    4x+11 = 2x+15
    4x - 2x = 15 - 11
    2x = 4
    x = 4/2
    x = 2


    b/
    3x +2 = 2x -5
    3x - 2x = - 5 -2
    x = - 7


    c/
    5x -3 = x -5
    5x - x = - 5+ 3
    4x = -2
    x = - 2/4
    x = - 1/2


    d/
    7x + 5 = - 3x +2
    7x + 3x = 2 -5
    10x = -3
    x = - 3/10

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