Respostas

2013-11-21T14:03:46-02:00
(3x+5y-2)+(5x-3y+2)=
3x+5y-2+5x-3y+2=
8x+2y



-(5x-3y+2)+(5x-3y+2)=
-5x+3y-2+5x-3y+2=
0