Mathématiques

Question

Resoudre les équations suivantes:
(E1):3x-1=-13                              (E5):11x-3=2x+9
(E2):-2x+5=8                               (E6):x/7=-7/4
(E3):5x=0                                     (E7):(-2x-5)(3x+2)=0
(E4):4-x=7                                    (E8):x²=50

1 Réponse

  • 3x-1 = -13
    3x = -13+1
    3x = -12
    x = -4


    -2x+5=8
    -2x+5-8=0
    -2x-3=0
    -2x=3
    x = -1,5

    5x=0
    x=0

    4-x = 7
    4-7 = x
    x=-3

    11x-3 = 2x+9
    11x-2x = 9+3
    9x = 12
    3x = 4
    x = 4/3


    x/7 = (-7/4)

    x = 7 (-7/4)
    x = -49/4


    (-2x-5)(3x+2) = 0

    -2x-5=0: x = - 2,5

    3x+2=0: 3x = -2: x = -2/3  


    x² = 50
    x = + racine(50) ou - racine(50)

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