Respostas

2014-04-04T13:50:35-03:00
-3....a....1
9.....b.....1
1....-2.....1

-3b-18+a-b-9a-6 = 0
a-9a-3b-b=18+6
-8a-4b = 24 :(4)
-2a-b = 6 .(-1)
2a+b = -6
2014-04-04T23:43:40-03:00