Well, I just need a little help in these... There are parts that I can't completely understand:

Find the complete interval of convergence for each series

1.

For this one... All I could do was set up the limit for the ratio test:

2.

For this one, I did a bit of work... But I need to know something:

This supposedly equals:

But I don't really know how the limit gets to 1.

Any help is appreciated.