Mathématiques

Question

Pouvez vous m'aidez:
a. x/3 = x/4 - 6/5
b. 5x/8 - 3/10 = 7x / 40
c. 2x/7 + 3/14 = x/7 - 1/14
d. 2/5 x - 1/9 = 3/9 x + 4/5

1 Réponse

  • a. x/3 = x/4 - 6/5
    X/3-X/4 = -6/5
    4/12x-3/12x = -6/5
    1/12x = -6/5
    x = -6/5 *12
    x = -6*12 /5
    x = - 72/5

    b. 5x/8 - 3/10 = 7x / 40 
    5/8x -7/40x = 3/10
    25/40x -7/40x =3/10
    18/40 x =3/10
    x =3/10 *40/18
    x = 120/180
    x =12/18
    x = 2/3

    c. 2x/7 + 3/14 = x/7 - 1/14
    2/7x -1/7x = -1/14 -3/14
    1/7x =-4/14
    1/7x = -2/7
    x = -2/7 x 7
    x =-14/7
    x = -2

    d. 2/5 x - 1/9 = 3/9 x + 4/5
    2/5x -3/9x = 4/5 +1/9
    18/45x -15/45 x = 36/45 +5/45
    3/45x = 41/45
    1/15x =41/45
    x = 41/45 *15
    x = 41/3

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