Mathématiques

Question




bonjour pouvez vous m’aider à résoudre ces équations? merci d’avance

a/ 5(x + 3) = 2x - 5
b/ 4(2x - 5) - 1 = 4x + 1
c/ (4x + 7) - (-2x + 6) = 8
d/ 3(2x - 5) + 2 = x-2

1 Réponse

  • Bonsoir,

    5(x+3) = 2x -5

    5x + 15 = 2x - 5

    5x - 2x =-15 - 5

    3x = 12

    x = 12 /3

    x = 4

    4(2x-5)-1=4x+1

    8x - 20 - 1 = 4x + 1

    8x - 21 = 4x + 1

    8x - 4x = - 20

    -4x = -20

    x = -20/-4

    x = 5

    (4x+7)-(-2x+6)=8

    (4x+7)(2x-6)=8

    8x²-24x+14x-42=8

    8x² - 10x = 48

    x(8x-10)=48

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

    6x - 15 + 2 = x-2

    6x - 13 = x - 2

    6x = x - 2 +13

    5x = 11

    x = 11/5

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