Select all the relations that represent a function. a.(2,3) (4,3) (6, 2) (5,7)
b.(2,3) (4,9) (6, 2) (5,7)
c.(5,4) (5, 7) (2,7) (3,5)
d..(4,8) (7,5) (8,4) (5,7)

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)