Mathématiques

Question

Équations maths 3ème

A) 3(x-1) + 2(x+3) = 0

B) -5(x+2) + 3(x-3) = 7

C) 5(2x-1) = 3(2x+5)

1 Réponse

  • A) 
    3(x - 1) + 2(x + 3) = 0
    3x - 3 + 2x + 6 = 0
    5x + 3 = 0
    5x = - 3
    x = - 3/5

    B)
    - 5(x + 2) + 3(x - 3) = 7
    - 5x - 10 + 3x - 9 = 7
    - 2x = 7 + 10 + 9
    - 2x = 26
    x = 26/-2
    x = - 13

    C)
    5(2x - 1) = 3(2x + 5)
    10x - 5 = 6x + 15
    10x - 6x = 15 + 5
    4x = 20
    x = 20/4
    x = 5

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