Help

Pls! does anybody know a shortcut for answering these types of questions in the future?

16. you're planning to buy a boat, a motor, and some miscellaneous boating equipment. the boat costs $325, the motor costs $225, and the equipment costs $79. if you've saved $438 toward these purchases, how much more do you need to save? a. $181 b. $281 c. $291 d. $191

Which of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?