Please help !!!

A company that manufactures a revolutionary aeration system (it combines coarse and fine bubble aeration components) had costs this year (year 1) of $8,000 for check valve components. Based on completion of a new contract with a distributor in China and volume discounts, the company expects this cost to decrease. If the cost in year 2 and each year thereafter decrease by $450, what is the equivalent annual cost for a five-year period at an interest rate of 10% per year