I think 10 is a recursive function because it has t(n-1) in the second part. I think it's also arithmetic since you aren't multiplying, but subtracting 1.

I think 11 is geometric explict since you have the 4^x and there is no h(x) in theh right part.

Stop reading and try figuring out 12 and 13 by yourself. :)))

I believe 12 is a arithmetic explict since you're doing 3/2n - 4, and there isn't g(n) in the right.

Perhaps I've made a mistake since in 13 I think it's supposed to be geometric recursive?

=^._.^=