Mathématiques

Question

Bonjour j'ai un exercice a faire pour demain :

1)Donne le résultat sous forme d'une fraction irréductible :

A = 2/5 - 15/20

B = 9/15 + 49/35

C = 25/8 - 27/24 +

-17/17

D = -2/3 x 9/4

E = 28/15 x (-20/6)

Merci d'avance

1 Réponse

  • Bonjour

    A = 2/5 - 15/20
    A = 2 x 4 / 5 x 4 - 15/20
    A = 8/20 - 15/20
    A = - 7/20

    B = 9/15 + 49/35
    B = 3 x 3 / 3 x 5 + 7 x 7 / 7 x 5
    B = 3/5 + 7/5
    B = 10/5
    B = 5 x 2 / 5 x 1
    B = 5

    C = 25/8 - 27/24 + -17/17
    C = 25/8 - 27/24 - 17/17
    C = 25/8 - 3 x 9 / 3 x 8 - 17/17
    C = 25/8 - 27/8 - 17/17
    C = - 2/8 - 17/17
    C = - 2/8 - 1
    C = - 2/8 - 1 x 8 / 1 x 8
    C = - 2/8 - 8/8
    C = - 10/8
    C = 2 x - 5 / 2 x 4
    C = - 5/4

    D = -2/3 x 9/4
    D = - 18/12
    D = 6 x - 3 / 6 x 2
    D = - 3/2

    E = 28/15 x (-20/6)
    E = - 560/90
    E = 10 x - 56 / 10 x 9
    E = - 56/9

Autres questions