The ice skating rink charges an hourly fee for skating and $3 to rent skates for the day. gillian rented skates and skated for 3 hours and was charged $21. which equation represents the cost, c(x), of ice skating as a function of x, the number of hours of skating? c(x) = 3x + 3 c(x) = 6x + 3 c(x) = 7x + 3 c(x) = 8x + 3