The cost, 𝐶, in dollars, of a gym membership for 𝑥 months can be described by the equation 𝐶 equals 70 dollars plus 25 dollars and 75 cents 𝑥. Which of the following describes what the number 25 dollars and 75 cents represents in this equation? a) The monthly increase in the cost. b) The total cost. c) The initial starting cost. d) The monthly decrease in the cost.
Let’s start by identifying the information that was given to us. 𝐶 is the cost of the gym membership. And 𝑥 is the number of months you were a member. We can go ahead and eliminate option b, the total cost, because we know that the variable 𝐶 represents the total cost. We can also eliminate option d, the monthly decrease in cost, because this equation only has addition. There is no decrease.
Our two options remaining are the monthly increase in the cost or the initial starting cost. You pay 70 dollars one time, no matter how many months you use the gym. And that means we would call the initial starting cost 70 dollars. And 25 dollars and 75 cents must be the monthly increase in the cost.
You pay 25 dollars and 75 cents every month you are a member.