Elena needs to earn at least $450 a week during her summer break to pay for college. She works two jobs. One as a swimming instructor that pays $9 an hour and the other as an intern in a genetics lab for $22.50 per hour. How many hours does Elena need to work at each job to earn at least $450 per week?

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: (