Respostas

2013-11-27T15:19:19-02:00
a1 = 12
an = 47
n = 2 + 6
n = 8
r = ?

an = a1 + (n - 1)r
47 = 12 + (8 - 1)r
7r = 35
r = 5

Logo, {12,17,22,27,32,37,42,47}

1 5 1