Bonjour,
Factoriser :
x²+2x+1 = (x + 1)²
4x² -12x+9 = (2x - 3)²
9(x+3)+(x+3)² = (x + 3) (x + 3 + 9) = (x + 3) (x + 12)
(x-6)² -16 = (x - 6 - 4) (x - 6 + 4) = (x - 10) (x - 2)
(2x-7)² -3(2x-7) = (2x - 7) (2x - 7 - 3) = (2x - 7) (2x - 10) = 2 (x - 5) (2x - 7)