Mathématiques

Question

bj un exos a faire pour demain help please : résoudre les equation suivantes: a) 5(x-2)=2x+(x+6) b)12-(5x-9)=4x+3 c) 5+3(2x+2)=6-4(x+1)

2 Réponse

  • a) 5x-10 =2x+x+6 = 5x-2x-x =6+10

    = 2x =16  x = 16/2 = 8

     

    b) 12 -5x+9 = 4x+3

    = -5x-4x = 3-12

    = -9x = -9 donc x = 1

     

    c) 5 +6x+6 = 6-4x-1

    = 6x+4x =6-1-6-5

    = 10x = -18 x = -18/10 = -9/5

  • 5(x-2)=2x+(x+6)

    5x - 10 = 2x + x + 6

    5x - 10 = 3x + 6 

    2x -10 = 6

    2x = 16 
    x = 16/2
    x = 8

    12 -(5x -9)=4x+3
    12 -5X + 9 = 4x +3

    -5x +21 = 4x + 3
    -9x +21 = 3
    -9x = -18
    x= 18/9 = 2 

    5+3(2x+2)=6-4(x+1)

    5 + (6x + 6) = 6 -(4X + 4)
    5 + 6X + 6 = 6 -4X -4
    6X + 11 = -4X + 2
    10x + 11 = 2
    10x = -9
    x = -9/10  

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