If possible, set up a proportion that could be used to solve for x. if not possible explain why

Answer this 30 points and brainliest!

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

Part a: sam rented a boat at $225 for 2 days. if he rents the same boat for 5 days, he has to pay a total rent of $480. write an equation in the standard form to represent the total rent (y) that sam has to pay for renting the boat for x days. (4 points)