You and a friend sign up for a health club. It costs $50 to join, plus $20 a month. However, the first 100 customers can sign up for $30, plus $20 a month. Your friend is customer 100, and you are 101. If the accumulated cost for each membership were graphed, what would it look like? What would the difference be between your accumulated cost and your friend's accumulated cost at any given month?

Question

You and a friend sign up for a health club. It costs $50 to join, plus $20 a month. However, the first 100 customers can sign up for $30, plus $20 a month. Your friend is customer 100, and you are 101. If the accumulated cost for each membership were graphed, what would it look like?  What would the difference be between your accumulated cost and your friend's accumulated cost at any given month?

anonymous · Answer

Look at this like an equation:

y = mx + b
Where y is total cost over time, b is initial cost (when months = 0), and m is the slope or the price per month. Oh, and x is the number of months.

What are the two equations for the 100th customer and the 101st customer.