Please help last one here

What is the 9th term in the geometric sequence described by this explicit formula? an=-6. (2)(n-1) apex

I’m still confused on how to work the percentages

Carla is saving money for a trip this summer. she already has some money in her savings account and will add the same amount to her account each week. at the end of 2? weeks, carla has? $130. at the end of 8? weeks, she has? $280. write a linear function in the form y=mx+b to represent the amount of money m that carla has saved after w weeks.