Classify each sequence as arithmetic, geometric, Fibonaccitype, or none of these. Find an expression for the general term if it is one of these types; otherwise, give the next two terms.

a. \(5,10,15,20, \cdots\)

b. \(5,10,20,40, \cdots\)

c. \(5,10,15,25, \cdots\)

d. \(5,10,20,35, \cdots\)

e. \(5,50,500,5,000, \cdots\)

f. \(5,50,5,50, \cdots\)