Hey guys I can't seem to get the answer for this so thanks if anybody could help:
The rth term of a series is 3^(r-1)+2r. Find the sum of the first n terms.
$\displaystyle \sum_{r=1}^{ n} 3^{r-1}+2r = \left( \sum_{r=1}^{ n} 3^{r-1} \right)+ \left( \sum_{r=1}^{ n} 2r \right) $
The first of these is a finite geometric series which you should be able to sum
and the second is a finite arithmetic series which you should also be able to sum
RonL