Respostas

2014-08-18T19:14:01-03:00
6 x - 12 y + 3 ( 6 y + 3 )
6 x - 12 y + 18 y + 9
6 x + 6 y + 9
2014-08-18T19:18:43-03:00
6x-12y+3.(6y+3)=

6x-12y+18y+9=

6x+6y+9