Sorry about the caps lock and exclamation points, but I have a time limit and these two questions are really stumping me!

1.)evaluate

i kept getting 1283.5, but i know that can't be right...

also!

2.)The sum of a geometric series is -1023 and its first term is -3. If the last term is -768, what is the common ratio?

please supply you work if you have the time! i would like to understand this, as well as get a good grade! ..