1. ## Series Help

sum (1+2^j)3^j, j=1..infinity

determine whether the series convergent or divergent, and find its sum

how do you find the limit of this?

2. Originally Posted by justin016
sum (1+2^j)3^j, j=1..infinity

determine whether the series convergent or divergent, and find its sum

how do you find the limit of this?
Note that $\sum_{j = 1}^\infty (1 + 2^j)3^j = \sum_{j = 1}^\infty 3^j + \sum_{j = 1}^\infty 6^j$

Now what kind of series are those? And what can you say about them?