I need a specific equation for a HP17b Calculator?

Question

The equation I require is for a finance product called Finance Lease specifically on motor vehicles using balloon payments, spread rentals or initial deposits and yield interest rates. Its the sort of thing you would either have or not and at this moment I don't have. Any ideas as to where I could find it or links would be greatly appreciated.

Answer 1

The manual for the HP17b may be posted at the HP website.

Answer 2

Not in this site, sorry.  Try mathematics/ finance, etc.