Amy and Eduardo are selling cheesecakes for a school fundraiser. Customers can buy French silk cheesecakes and chocolate marble cheesecakes. Amy sold 9 French silk cheesecakes and 10 chocolate marble cheesecakes for a total of $285. Eduardo sold 6 French silk cheesecakes and 5 chocolate marble cheesecakes for a total of $165. Find the cost each of one French silk cheesecake and one chocolate marble cheesecake.