Mathématiques

Question

A=4(x+5)=10x+3. B= 3(x-2)=6(x+4).

C=7x-(5x+3)=5(x-3)+2.
D=7(n+2)-3=25-(3n+4)

2 Réponse

  • A = 4(x + 5) = 10x + 3
    4x + 20 = 10x + 3
    4x - 10x = 3 - 20
    - 6x = - 17
    x = 17/6

    B = 3 (x - 2) = 6 (x + 4).
    3x - 6 = 6x + 24
    3x - 6x = 24 + 6
    - 3x = 30
    x = - 30/3
    x = - 10

    C = 7x - (5x + 3) = 5 (x - 3) + 2
    7x - 5x - 3 = 5x - 15 + 2
    7x - 5x - 5x = - 15 + 2 + 3
    - 3x = - 10
    x = 10/3

    D = 7 (n + 2) - 3 = 25 - (3n + 4)

    7n + 14 - 3 = 25 - 3n - 4
    7n + 3n = 25 - 4 - 14 + 3
    10n = 10
    n = 10/10
    n = 1
  • A=4(x+5)= 10x +3
    4x +20= 10x +3
    4x +20 -20 -10x= 10x +3 -20 -10x
    -6x= -17
    -6x/ -6= -17/ -6
    x= 17/6

    B= 3(x-2)=6(x+4)
    3x -6= 6x +24
    3x -6 +6 -6x= 6x +24 +6 -6x
    -3x= 30
    -3x/-3= 30/-3
    x= -10

    C= 7x-(5x +3)= 5(x-3) +2
    7x -5x -3= 5x -15 +2
    7x -5x -3 +3 -5x= 5x -15 +2 +3 -5x
    -3x= -10
    -3x/-3= -10/-3
    x= 10/3

    D= 7(n+2) -3= 25-(3n +4)


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