Mathématiques

Question

bonjour aidez moi svp
on donne
A=144x+64+81x²-(9x+8)(2x+4)
1) developper et reduire A
2)factoriser A
calculer A pour x=-2
4)resoudre l'equation A=0

1 Réponse

  • 1/

    A=144x+64+81x²-(9x+8)(2x+4)

    A=144x+64+81x²-(18x²+36x+16x+32)

    a = 114x+64+81x²-18x²-52x-32

    a = 63x²+62x+32

    2/

    A=144x+64+81x²-(9x+8)(2x+4)

    a =(9x-8)²-(9x-8)(2x+4)

    a =(9x-8)(9x-8-2x-4)

    a=(9x-8)(7x-12)

    3/

    a = 63x² +62x+32

    a = 63(-2)²+62(-2) +32

    a =252 -124+32

    a =160

    4/

    (9x-8)(7x-12)=0

    9x-8 = 0            7x+12 =0

    9x =8                    7x = -12

    x =8/9                     x = -12/7

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