Mathématiques

Question

bonjour!
pouvez-vous m'aider pour cet exercice?
5(x-1)+3(2-x)=0.
7(x+4)-3(x+2)=x+7.
2(x-1)-3(x+1)=4(x-2).
-1/2x+3=x-7.
3/2x+4=2x-5.
3x+5=-7/9.

merci ďavance❤

2 Réponse

  • Bonjour,

    a. [tex]5.(x - 1) + 3.(2 - x) = 0[/tex]

    [tex]5x - 5 + 6 - 3x = 0[/tex]

    [tex]2x + 1 = 0[/tex]

    [tex]2x = - 1[/tex]

    [tex]x = - \frac{1}{2} [/tex]

    b. [tex]7.(x + 4) - 3.(x + 2) = x + 7[/tex]

    [tex]7x + 28 - 3x - 6 = x + 7[/tex]

    [tex]4x + 22 = x + 7[/tex]

    [tex]3x + 15 = 0[/tex]

    [tex]3x = - 15[/tex]

    [tex]x = - \frac{15}{3} = - 5[/tex]

    c. [tex]2.(x - 1) - 3.(x + 1) = 4.(x - 2)[/tex]

    [tex]2x - 2 - 3x - 3 = 4x - 8[/tex]

    -x -5 = 4x -8
    -5x +3 = 0
    -5x = -3
    x = -3/-5 =0.6
  • bonjour

    5(x-1)+3(2-x)=0.

    5 x - 5 + 6 - 3 x = 0

    2 x = - 6 + 5

    2 x = - 1

    x = - 1/2

    7(x+4)-3(x+2)=x+7.

    7 x + 28 - 3 x - 6 = x + 7

    7 x- 3 x- x = 7 - 28 + 6

    3 x = -  15

    x = - 15/3 = - 5

    2(x-1)-3(x+1)=4(x-2).

    2 x - 2 - 3 x - 3 = 4 x - 8

    - x - 4 x = - 8 + 2 + 3

    - 5 x = - 3

    x = 3/5

    -1/2x+3=x-7.

    - 0.5 x - x = - 7 - 3

    - 1.5 x = - 10

    x =   100/15  = 20/ 3

    3/2x+4=2x-5.

    3 x / 2 - 2 x = - 5 - 4

    3 x /2 - 4 x /2 = - 9

    - x /2 = - 18/2

    - x = - 18

    x = 18

    3x+5=-7/9.

    3 x = - 7/9 - 5

    27 x /9 = - 7/9 - 45/9

    27 x = - 52

    x = -  52/27

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