How to solve 3.16 times 10 to the 3rd power

Write an algebraic expression for the word expression the quotient of c and 8

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

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?