Mathématiques

Question

Je n'arrive pas a faire les equation aider moi svp le numero 40/41/42/43
Je n'arrive pas a faire les equation aider moi svp le numero 40/41/42/43

2 Réponse

  • 40)

     a)

     

    3x+2=2x-5

    3x-2x=-5-2

    x=-7

     

    b)

     

    -3x+7=3x-11

    -3x-3x=-11-7

    -6x=-18

    x=-18/-6

    x=3

     

    41)

     

    a)

     

    -5x+4=6x+8

    -5x-6x=8-4

    -11x=4

    x=4/-11

     

    b)

     

    5-9x=-3x+2

    -9x+3x=2-5

    -6x=-3

    x=-3/-6

    x=0.5

     

    42)

     

    a)

     

    2(x-5)=3x+5

    2*x+2*5=3x+5

    2x+10=3x+5

    2x-3x=5-10

    -x=-5

    x=5

     

    b)

     

    -4(3+x)=2x-6

    -4*3-4*x=2x-6

    -12-4x=2x-6

    -4x-2x=-6+12

    -6x=6

    x=6/-6

    x=-1

     

    43)

    a)

     

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

    -3*2-3*x=1-5x

    -6-3x=1-5x

    -3x+5x=1+6

    2x=7

    x=7/2

    x=3.5

     

    b)

     

    4-7(2-x)=5-4x

    4-7*2-7*(-x)=5-4x

    4-14+7x=5-4x

    7x+4x=5-4+14

    11x=15

    x=15/11

     

     

  • 40) 3x+2 = 2x-5                  -3x+7=3x-11

           x +7 = 0                         -6x+18=0

           x=-7                                x=3

     

    41) -5x +4= 6x+8             5-9x=-3x+2

          -11x-4=0                      3-6x=0

           x= 4/-11                       x= 1/2

     

    42)2(x-5)=3x+5              -4(3+x)=2x-6

         2x-10=3x+5               -12-4x=2x-6

         -x-15=0                         -6x-6=0

        x= -15                             x= -1

     

    43) -3(2+x)=1-5x          4-7(2-x)= 5-4x   

          -6-3x=1-5x                4-14+7x= 5-4x

         -7+2x=0                     -10+7x=5-4x

         x= 7/2                            -15+11x=0

                                              x= 15/11