What term best describes the political and economic relationship between lords and vassals based on the exchange of land for loyalty and military service. a. magyar commitment b. papal supremacy c. mutual obligations

You are given the first four terms of an arithmetic sequence. why might you use a recursive formula? why might you use an explicit formula? under what conditions might a recursive formula be preferred over the explicit formula? under what conditions might an explicit formula be preferred over the recursive formula? pleasss ! sorry if it's a long question: (