Mathématiques

Question

Calculs avec relatifs et fractions. Donner le résultat sous la forme la plus simple
A= 4/9* 3/5- 2/5
B= -2/3-(-1/6)-3/2
C= 1-(1/2+1/3-1/4)
D= 5/9-(-1/2)-1/6
E= (1/2-2/3)-(5/6-3/4)
F= 1/10+(-1/4+7/20)-(7/10-3/2)
Merci

1 Réponse

  • A= 4/9* 3/5- 2/5
    A = 12/45 - 2/5
    A = 12/45 - 2 x 9 / 5 x 9
    A = 12/45 - 18/45
    A = - 3/45
    A = 3 x - 1 / 3 x 15
    A = - 1/15

    B= -2/3-(-1/6)-3/2
    B = - 2/3 + 1/6 - 3/2
    B = - 2 x 2 / 3 x 2 + 1/6 - 3 x 3 / 2 x 3
    B = - 4/6 + 1/6 - 9/6
    B = - 12/6
    B = 6 x - 2 / 6 x 1
    B = - 2

    C= 1-(1/2+1/3-1/4)
    C = 1 x 12 / 1 x 12 - (1 x 6 / 2 x 6 + 1 x 4 / 3 x 4 - 1 x 3 / 4 x 3)
    C = 12/12 - (6/12 + 4/12 - 3/12)
    C = 12/12 - 7/12
    C = 5/12

    D= 5/9-(-1/2)-1/6
    D = 5/9 + 1/2 - 1/6
    D = 5 x 2 / 9 x 2 + 1 x 9 / 2 x 9 - 1 x 3 / 6 x 3
    D = 10/18 + 9/18 - 3/18
    D = 16/18
    D = 2 x 8 / 2 x 9
    D = 8/9

    E= (1/2-2/3)-(5/6-3/4)
    E = (1 x 6 / 2 x 6 - 2 x 4 / 3 x 4) - (5 x 2 / 6 x 2 - 3 x 3 / 4 x 3)
    E = (6/12 - 8/12) - (10/12 - 9/12)
    E = - 2/12 - 1/12
    E = - 3/12
    E = 3 x - 1 / 3 x 4
    E = - 1/4

    F= 1/10+(-1/4+7/20)-(7/10-3/2)

    F = 1 x 2 / 10 x 2 + (- 1 x 5 / 4 x 5 + 7/20) - (7 x 2 / 10 x 2 - 3 x 10 / 2 x 10)
    F = 2/20 + (- 5/20 + 7/20) - (14/20 - 30/20)
    F = 2/20 + (2/20) - (- 16/20)
    F = 2/20 + 2/20 + 16/20
    F = 20/20
    F = 1

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