Bonjour
Factoriser :
À) ( x + 2) ² - 9
= (x + 2)^2 - 3^2
= (x + 2 - 3)(x + 2 + 3)
= (x - 1)(x + 5)
B) 25x ² - 9 - (5x+3)(5-x).
= (5x)^2 - 3^2 - (5x + 3)(5 - x)
= (5x - 3)(5x + 3) - (5x + 3)(5 - x)
= (5x + 3)(5x - 3 - 5 + x)
= (5x + 3)(6x - 8)
= (5x + 3) * 2(3x - 4)
= 2(5x + 3)(3x - 4)
C) (x+2) ² -(x+2)
= (x + 2)(x + 2 - 1)
= (x + 2)(x + 1)
D) 9x puissance 4 - 12x ² +4
= (3x^2)^2 - 3(2x)^2 + 4
= 3x^2(3x^2 - 4) + 4