Respostas

2014-03-07T11:12:33-03:00
- 66 = - 6 + ( n - 1) -3
- 66 + 6 = -3n + 3
 - 60 - 3 = - 3n
   3n = 63
   n= \frac{63}{3}
   n=21.
1 5 1