Réponses

2014-04-24T16:31:23+02:00
Exercice 112 :
a) (3x+1)*(3x+1) = 3 x^{2} + 3x*1 + 1* 3x + 1^{2}
= 3 x^{2} +3x+3x+1 3 x^{2} +6x+1
b) (7-x)*(7-x) = 7 x^{2} - 7*x -x*7 + x^{2}
7 x^{2} -7x-7x +  x^{2} = 7 x^{2} -14x + x^{2}
c) (9-5x)*(9+5x) = 9^2 +9*5x-9*5x-(5x)^2
81+45x-45x-25x^2= 81 - 25x^2

Exercice 113 :
a) 36 -60x+25x^2 = (5x - 6)^2
b)9x^2+42x+49 = (3x+7)^2
c) et d) je ne sais pas... Désolé