For explicit equations with the first term, you use the form [tex]f(n)=f_{1}+d(n-1)[/tex]. (f of 1 is the first term, d is the common difference, n is the step number)
However, since it is an admission fee before you go on rides, you do not need the -1 because it is not from the first term. Then, you can plug the values you know in.
f(n)=5+2n
