The ice-skating rink charges an hourly fee for skating and $3 to rent skates for the day. Gillian rented skates and skate it for three hours and was charged $21. which equation represents the cost, c(x), of ice skating as a function of x, The number of hours skating?
A. C(x)=3x+3
B. C(x)=6x+3
C. C(x)=7x+3
D. C(x)=8x+3
Subtract $3 from $21 to get the cost of skating for three hours without the rental fee. 21-3=18. $18 was spent on skating for three hours so you'll divide 18 by 3 to get the hourly rate. 18/3=6. C(x)=6x+3