Mathématiques

Question

Résoudre algébriquement chaque équation :

A= 3x-1/2 = -3/4-5x
B= 1/4x + 5/2 = -x+1
C= -4/5 + y = 3/10 - 1/2y
D= 5/2a + 1/4 = 1/4a + 2/5

Merci de vos aides :)

1 Réponse

  • A= 3x-1/2 = -3/4-5x
    A = 3x + 5x = 1/2 - 3/4
    A = 12/4x + 20/4x = 2/4 - 3/4
    A = 32x = - 1
    A = x = - 1/32

    B= 1/4x + 5/2 = -x+1
    B = 1/4x + x = 2 - 5/2
    B = 1/4x + 4/4x = 8/4 - 10/4
    B = x + 4x = 8 - 10
    B = 5x = - 2
    B = x = - 2/5
    B = x = - 0,4

    C= -4/5 + y = 3/10 - 1/2y
    C = y + 1/2y = 3/10 + 4/5
    C = 10/10y + 5/10y = 3/10 + 8/10
    C = 10y + 5y = 3 + 8
    C = 15y = 11
    C = y = 11/15

    D= 5/2a + 1/4 = 1/4a + 2/5

    D = 5/2a - 1/4a = 2/5 - 1/4
    D = 25/10a - 5/20a = 8/20 - 5/20
    D = 25a - 5a = 8 - 5
    D = 20a = 3
    D = a = 3/20
    D = a = 0,15

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