Respostas

2014-03-13T21:09:57-03:00
A1=10
an=60
N:?
R:5
An=a1+(n-1).R
60=10+(n-1).5
60=10+5n-5
60=5+5n
5n=60-5
55:5
11
2014-03-13T21:11:15-03:00
An = a1 + (n - 1) . r 60 = 10 + (n-1) . 5 60 = 10 + 5n - 5 60 = 5 + 5n 60 - 5 = 5n 55 = 5n n = 55/5 n = 11 termos É isso.