Répondre :
(x+1/3)²-4(x-1/3)²
=(x+1/3)²-(2x-2/3)²
=(x+1/3+2x-2/3)(x+1/3-2x+2/3)
=(3x-1/3)(-x+1)
=(x+1/3)²-(2x-2/3)²
=(x+1/3+2x-2/3)(x+1/3-2x+2/3)
=(3x-1/3)(-x+1)