Question

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

Answer 1

C(x)=rx+s  we are told that x=3, c(x)=21, and s=3

21=3r+3  divide both sides by 3

7=r+1  subtract 1 from both sides

6=r  so now c(x) becomes:

c(x)=6x+3

Answer 2

Answer: $c(x)=6x+3$

Step-by-step explanation:

Given: The fixed cost charged by ice skating rink  = $3

The total charge of renting skates for 3 hours =$21

Let the hourly fee of skates for be 'c', then we have the following equation:-

$3(c)+3=21\\\\\Rightarrow\3c=21-3\\\\\Rightarrow\ 3c=18\\\\\Rightarrow\ c=6$

Hence, the hourly fee for skating = $6

Let the number of hours of skating represented by x, then we have the following equation  represents the cost, c(x) is given by :

$c(x)=6x+3$