sarah work at a concession stand for 2 hours and erans 22.50$, but if she works for 4 hours she earns $45. what is the rate of change

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?

Ineed here’s a picture of the question

Tom travels between the two mile markers shown and then finds his average speed in miles per hour. select the three equations that represent this situation.