Mathématiques

Question

Bonsoir. .j'ai besoin d'aides

A = 2/3-3 / 1-2/9

B = 2/5 + 3/5 : ( 1-1/10)

C = 5+ ( 1/8+1) : 3/4

"/ " = barre de fraction

Merci.

2 Réponse

  • A = -2,55
    B = 1,04
    C = 6,5
  • Bonsoir

    A = 2/3-3 / 1-2/9  = (2/3 - 9/3) : ( 9/9 - 2/9) = -7/3 : 7/9 = - 7/3 x 9/7 = - 63/21 ou - 9/3

    B = 2/5 + 3/5 : ( 1-1/10) = 2/5 + 3/5 : ( 10/10 - 1/10) = 2/5 + 3/5 : 9/10 = 2/5 + 3/5 x 10/9
    = 2/5 + 30/45 = 18/45 + 30/45 = 48/45

    C = 5+ ( 1/8+1) : 3/4  = 5 + ( 1/8 +8/8) : 3/4 = 5 + 9/8 : 3/4 = 5 +9/8 x 4/3 = 5 + 36/24
    = 5 + 9/6 = 30/6 + 9/6 = 39/6  = 13/2


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