Réponses

2013-11-24T22:33:12+01:00
A=3y²+12y+2y+8
  =3y²+14y+8

B=6y²-10y+3y-5
  =6y²-7y-5

C=12y²+28y-6y-14
  =12y²+22y-14

D=y²-2y-3y+6
  =y²-5y+6

E=(16y²+56y-8y-28)-(15y²-45y+18y-54)
  =16y²+56y-8y-28-15y²+27y+54
  =y²+75y+26

voila, voila !