Mathématiques

Question

bonjour quelqu'un peut m'aider pour cette exercice merci d'avance


EXERCICE :


A. 5 (x+3) = 3 + (2x-6)


B. x+3 - 4x-1 = 3 + x

------ ------- ----
,,,3,,,,,, 6,,,,,,,,,,,,,,,,,3


C. -2 (2x-4) = 6x - (-3+x)


D. 4x - 2 + (5x-1) = -3 (7-x)


E. x+5 - 2x-7 = 2 + 3x

------ ------ -----
,,,,, 2 ,,,,,,,5 ,,,,,,,,,,,, 10

1 Réponse

  • Bonjour,

    A. 5 (x+3) = 3 + (2x-6)

    5x + 15 = 3 + 2x - 6

    5x - 2x = - 6 - 15

    3x = - 21

    x = - 21/3

    x = - 7

    B. (x + 3) / 3 - (4x - 1) / 6 = (3 + x) / 3

    (2x + 6) / 6 - (4x - 1) / 6 = (6 + 2x) / 6

    2x + 6 - 4x + 1 = 6 + 2x

    2x - 4x - 2x = 6 - 6 - 1

    - 4x = - 1

    x = 1/4

    C. -2 (2x-4) = 6x - (-3+x)

    - 4x + 8 = 6x + 3 - x

    - 4x - 6x + x = 3 - 8

    - 9x = - 5

    x = 5/9

    D. 4x - 2 + (5x-1) = -3 (7-x)

    4x - 2 + 5x - 1 = - 21 + 3x

    4x + 5x - 3x = - 21 + 2 + 1

    6x = - 18

    x = - 18/6

    x = - 3.

    E. (x + 5) / 2 - (2x - 7) / 5 = (2 + 3x) / 10

    (5x + 25) / 10 - (4x - 14) / 10 = (2 + 3x) / 10

    5x + 25 - 4x + 14 = 2 + 3x

    5x - 4x - 3x = 2 - 25 - 14

    - 2x = - 37

    x = 37/2.

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