Registration fee and monthly fee?

Question

Courtney paid a one time registration fee to join a fitness club. She also pays a monthly fee. After three months she had paid $315. After seven months she had paid $535. Determine the registration fee and the monthly fee.

Answer 1

Let R = registration fee and M = monthly fee.

3M = the monthly fee for three months and the total for three months is

R + 3M = 315

 

7M = the monthly fee for 7 months and the total for 7 months is

R + 7M = 535

 

Subtract the first from the second:

4M = 220 => M = 55 and R = 150