What formula do I need to use to solve this? I DO NOT need the excel formula because we don't use excel for my finance class. I just need the regular formula to solve this.

19. A pottery factory purchases a continuous belt conveyor kiln for $51,000. A 8.1% APR loan with monthly payments is taken out to purchase the kiln. If the monthly payments are $529.72, over what term is this loan being paid? A. 13 years B. 12 years C. 14 years D. 11 years