Mathématiques

Question

Bonjour , je voudrais de l'aide pour résoudre des équations :
a) 1+4x=x-3
b) 3x+7=5(x+1)
c) 2(x-1)=3(2+x) 

d) (x-4)(x-1)=0

e) (2x-1)(x+2)=0

f) (3x+4)+(2-4x)=0 

2 Réponse

  • a = 1 +4x = x-3

    a = 4x-x = -3-1

    a = 3x = -4

       x = -4/3

     

    b) 3x+7 = 5(x+1)

         3x +7 = 5x +5

        3x -5x = 5-7

        -2x = -2

         x = 1

     

    c) 2(x-1) = 3(2+x)

     

    2x-2 = 6 +3x

    2x-3x = 6+2

    -x = 8

    d) (x-4)(x-1) = 0

    soit x-4 = 0 donc x = 4

    soit x-1  = 0 alors x = 1

     

    e) (2x-1)(x+2) = 0

    soit 2x-1 = 0 donc 2x= 1 et x = 1/2

    soit x+2 = 0 alors x = -2

    f) (3x+4)+(2-4x ) = 0

    3x+4+2-4x = 0

    -x+6 = 0

    -x = -6

    x = 6

  • a) 1+4x = x-3

        +4x -x = -1 -3

          +3x = -4

              x = -4/3

    b) 3x +7 = 5(x+1)

       3x +7 = 5x +5

        3x -5x = -7 +5

        -2x = -2

           x = -2/2 = +1

    c) 2x -2 = 6 +3x

        2x -3x = +2 +6

        -x = 8

         x = -8

    d) x-4=0 x= 4

    x-1 = 0  x = 2   

    e) 2x-1 = 0 --------     2x = 1-------------- x = 1/2

    x+2=0 x = -2

    f) 3x+4=0

    3x = -4

    x= -4/3

    2-4x = 0

    -4x = -2

    x = -2/4 = -1/2

     

    f) 

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