Mathématiques

Question

ex 1 : Supprimer les paranthéses et réduire : 5x² + (-2x + 8) - (6x² - 5x + 3)

ex 2 : Développer et réduire les expressions suivantes :

A = -7(3x - 8)
B = 3x(-5x +9)
C = (2x - 3)(-7 x + 6)

ex 3 :! Factorisez au maximum les expressions suivantes :

A = 28x - 35
B = 6x² + 8x
C = 16x - 4
D = (2x - 3)(x + 5) - (2x - 3)(-3x + 4)
E = (3x + 1)(5x - 1) + (5x-1)

2 Réponse

  • Ex : 1

    5x
    ² + (-2x+8) - (6x²-5x+3)
    = 5x² - 2x + 8 -6x² + 5x -3
    = -x² +3x + 5

    Ex : 2

    A = -7(3x - 8)
    = -21x + 56

    B = 3x(-5x +9)
    = -15x² + 27x

    C = (2x - 3)(-7 x + 6)
    = -14x² + 12x + 21x - 18
    = -14x² + 33x - 18

    Ex : 3

    A= 28x - 35
    = 7 ( 4x - 5)

    B= 6x²+8x
    = 2x (3x+4)

    C = 16x - 4
    = 4 ( 4x - 1) 

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

    E = (3x + 1)(5x - 1) + (5x-1)
    = (5x-1) (3x+1+1)
    = (5x-1) (3x+2)
  • Bonjour , 
    Ex.1 : 
    5x² - 2x +8 - 6x² + 5x - 3
    = -x² +3x +5
    Ex.2 :
    A = -21x +56
    B = -15x² +27x
    C = -14x² +12x +21x -18
    C = -14x² +33x -18
    Ex. 3: 
    A = 7(4x-5)
    B = 2x ( 3x + 4)
    C = 16x - 4
    C = 4 ( 4x - 1) 
    D = (2x-3) [ (x+5) - (-3x+4) ]
    D = (2x-3) [ x+5 +3x - 4 ]
    D = (2x-3) ( 4x -1) 
    E = (5x-1) [ (3x+1) +1 ]
    E = (5x-1) (3x+2 )

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