Mathématiques

Question

Aide svp
A = 25x^2 - 4
B = (2x - 3)(5x + 2)
C = 4x(2x+1)^2
D = (x+1)(2x-3)+(x+1)(-3x+2)
E = x^2 -6x+9
F = (x-3)^2-16

a : développer 2 expressions sauf B et D
b : factoriser 3 expressions sauf D

^2= au carré

merci

2 Réponse

  • a. 
    F = (x - 3)² - 16
    F= x² - 6x + 9 - 16
    F= x² - 6x - 7


    C = 4x(2x + 1)²
    C= 4x(4x² + 4x + 1)
    C= 16x³ + 16x² + 4x

    b. 
    A= 25x² - 4
    A= (5x)² - 2²
    A= (5x + 2)(5x - 2)

    F= (x - 3)² - 16
    F= (x - 3)² - 4²
    F= (x - 3 - 4)(x - 3 + 4)
    F= (x - 7)(x + 1) 

    E= x² - 6x + 9
    E= x * x - 2 * 3* x + 3²
    E= (x - 3)²
  • Bonjour

    Développons

    C = 4x(2x+1)^2
    C = 4x(4x² + 4x + 1)
    C = 16x^3 + 16x² + 4x

    F = (x-3)^2-16
    F = (x² - 6x + 9) - 16
    F = x² - 6x + 9 - 16
    F = x² - 6x - 7


    Factorisons
    A = 25x^2 - 4
    A = (5x+2)(5x-2)



    E = x^2 -6x+9
    E = (x-3)² ou (x-3)(x-3)

    F = (x-3)^2-16
    F = [(x-3)+4][(x-3)-4]
    F = (x-3+4)(x-3-4)
    F = (x+1)(x-7)


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