Calculate the surface area?

Please help

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?

If you can solve all of these i will give ! - 4% of 190 - 4% of 162.5 - 4% of 140 - a 4% increase from 155.1 - a 4% increase from 159.8

Me! i really need to get this right before 9. prove the divisibility of 7^6+7^5-7^4 by 11. use factoring so you get a number times 11. just tell me the number. i need this done asap