Réponses

2014-04-18T16:25:27+02:00
(x-5)(x-1) = x*x+x*(-1)-5*x-5*(-1) = x²-x-5x+5 = x²-6x+5

(x-3)²-4 =
(x²-2*x*3+3²)-4 = x²-6x+9-4 = x²-6x+5

(x-5)(x-1) = x²-6x+5 = (x-3)²-4