Mathématiques

Question

bonjour jai besoin daide !
factoriser les expressions .
A=(2x-7)²-49
B=(3x-3)(2x+7)-(9x²-9)
C=4(1-6x)(7x-2)+9(x-3)(7x-2)
D=(5x-8)²-(2x+9)²
merci beaucoup d'avance !!!

1 Réponse

  • A = (2x - 7)² - 49
    A = (2x - 7)² - 7²
    A = (2x - 7 + 7) ( 2x - 7 - 7)
    A = 2x (2x - 14)
    4= 4x( x - 7)

    B= (3x - 3) (2x + 7) - (9x² - 9)
    B= (3x - 3)(2x + 7) - (3x - 3)(3x + 3)
    B = (3x - 3) [(2x + 7) - (3x + 3)]
    B = (3x - 3) [2x + 7 -3x - 3]
    B= (3x - 3) (-x + 4)
    B = 3 ( x - 3)( - x + 4)

    C=4 ( 1 - 6x) (7x - 2) + 9 (x - 3)(7x - 2)
    C=  (7x - 2)  [ 4 ( 1 - 6x) + 9 ( x - 3)]
    C =( 7x - 2)  [4 - 24x + 9x - 27]
    C = ( 7x - 2) ( - 15x - 23)
    C = (7x - 2) ( - 15x - 23 )

    D =( 5x - 8)² - (2x + 9)²
    D = (5x - 8 + 2x + 9) ( 5x - 8 -(2x + 9)
    D = ( 7x + 1) ( 5x - 8 -2x - 9)
    D = ( 7x + 1) ( 3x - 17)

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