Mathématiques

Question

9x = 3(x+8)
3(2t + 5) = 4(5t+7)
2(3x + 4) - 5(1 - 2x) = 7(2x-3) + 12

2 Réponse

  • Bonsoir,

    9x = 3(x+8)
    9x = 3x + 24
    9x - 3x = 24
    6x = 24
    x = 24/6
    x = 4


    3(2t + 5) = 4(5t+7)
    6t + 15 = 20t + 28
    6t - 20t = 28 - 15
    -14t = 13
    t = -13/14


    2(3x + 4) - 5(1 - 2x) = 7(2x-3) + 12
    6x + 8 - 5 + 10x = 14x - 21 + 12
    6x + 10x - 14x = -21 + 12 - 8 + 5
    2x = -12.
    x = -12/2
    x = -6


  • 9x = 3x +24
    9x - 3x = 24
    6x = 24
    x = 24/6
    x = 4

    3(2t + 5) = 4(5t+7)
    6t + 15= 20t + 28
    15-28 = 20t - 6t
    -13 = 14t
    t = -13/14

    2(3x + 4) - 5(1 - 2x) = 7(2x-3) + 12
    6x + 8 - 5 + 10x = 14x - 21 + 12
    6x + 10x - 14x = -21 + 12 + 5 - 8
    2x = -12
    x = -6

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