Here's a link to your answer

https://web2.0calc.com/questions/sequence_38

Here's a answer to your question:

https://web2.0calc.com/questions/quadratics_17

Here's a link to your answer:

https://web2.0calc.com/questions/help-please_82361

Here's the link to the same problem that's been answered:

https://web2.0calc.com/questions/geometric-sequence_26

Thank you so much CPhill! I think the answer is 41/3+4/3=45/3 which is equivilent to 15.