Réponses

2013-03-05T14:53:49+01:00

(-5y+1)²-(2y-3)²

=-5y*2y+1²*2y+-5y*3²+1²*3²

=10y+2y²+15y²+3²

=10y +(2+15+3)y²

=10y+20y²

 

 

 

C'est sa je pense!!