Mathématiques

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Salut pouvez-vous m’aide Svp je comprends pas le travaille merci d’avance
Salut pouvez-vous m’aide Svp je comprends pas le travaille merci d’avance

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2 Réponse

  • Bonjour,

    1)

    a) M = 2/5 - 4/3 + 7/2

    M = (2 x 6) / (5 x 6) - (4 x 10) / (3 x 10) + (7 x 15) / (2 x 15)

    M = 12/30 - 40/30 + 105/30

    M = 77/30

    b) N = 2/3 - 5/3 x 3/2

    N = 2/3 - 15/6

    N = (2 x 2) / (3 x 2) - 15/6

    N = 4/6 - 15/16

    N = - 11/6

    c) L = (- 7/4 + 1/2) : (2/7 + 1/4)

    L = [- 7/4 + (1 x 2) / (2 x 2)] : [(2 x 4) /  (7 x 4) + (1 x 7) / (4 x 7)]

    L = (- 7/4 + 2/4) : (8/28 + 7/28)

    L = - 5/4 : 15/28

    L = - 5/4 x 28/15

    L = - 140/60

    L = (20 x - 7) /(20 x 3)

    L = - 7/3

    d) P = - 28/5 : - 21

    P = - 28/5 x - 1/21

    P = 28/105

    P = (7 x 4) / (7 x 15)

    P = 4/15

    2) Inverse de M = 30/77

    3) Opposé de M = - 77/30

    4)

    a)  M - N

    = 77/30 - (- 11/6)

    = 77/30 + (11 x 5) / (6 x 5)

    = 77/30 + 55/30

    = 132/30

    = (6 x 22) / (6 x 5)

    = 22/5

    b) N x L

    = - 11/6 x - 7/3

    = 77/18

    c) M : N

    = 77/30 : - 11/6

    = 77/30 x - 6/11

    = - 462/330

    = (66 x - 2) / (66 x 7)

    = - 2/7

    5)

    a) 2/3 (x - 1) =- 1/5 (x + 3) - 1/2

    2/3x - 2/3 = - 1/5x - 3/5 - 1/2

    20/30x - 20/30 = - 6/30x - 18/30 - 15/30

    20x - 20 = - 6x - 18 - 15

    20x + 6x = - 18 - 15 + 20

    26x = - 13

    x = - 13/26

    x =- 1/2

    b) (2x + 1) / 2 - x/3 = (x - 5) / 6

    (6x + 3) / 6 - 2x/6 = (x - 5) / 6

    6x + 3 - 2x = x - 5

    6x - 2x - x = - 5 - 3

    3x = - 8

    x = - 8/3

  • Réponse :

    Explications étape par étape

    Bonjour

    Calculer :

    M = 2/5 - 4/3 + 7/2

    M = 12/30 - 40/30 + 105/30

    M = 77/30

    N = 2/3 - 5/3 x 3/2

    N = 2/3 - 3/3 x 5/2

    N = 2/3 - 5/2

    N = 4/6 - 15/6

    N = -11/6

    L = (-7/4 + 1/2) : (2/7 + 1/4)

    L = (-7/4 + 2/4) : (8/28 + 7/28)

    L = (-5/4) : (15/28)

    L = -5/4 x 28/15

    L = -5/15 x 28/4

    L = -1/3 x 7

    L = -7/3

    P = (-28/5)/-21

    P = -28/5 x -1/21

    P = -28/21 x -1/5

    P = 4/3 x 1/5

    P = 4/15

    2) inverse de M : 30/77

    3) opposé de M : -77/30

    4) calculer :

    M - N = 77/30 - (-11/6) = 77/30 + 55/30 = 132/30 = (22 x 6)/(5 x 6) = 22/5

    N x L = -11/6 x -7/3 = 77/18

    M / N = (77/30) / (-11/6) = 77/30 x -6/11 = -77/11 x 6/30 = -7 x 1/5 = -7/5

    5) résoudre :

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

    2/3 x - 2/3 = -1/5 x - 3/5 - 1/2

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

    10/15 x + 3/15 x = 20/30 - 18/30 - 15/30

    13/15 x = -13/30

    x = -13/30 * 15/13

    x = -13/13 * 15/30

    x = -1/2

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

    [3(2x + 1)]/6 - 2x/6 = (x - 5)/6

    6x + 3 - 2x = x - 5

    4x - x = -3 - 5

    3x = -8

    x = -8/3

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