Well, we know that it costs $60 plus 5 per month for Alpha Fitness Club.
We also know that it costs $20 plus 10 per month for Omega Fitness Club.
In order to find out which one would cost the most, we must add the additional costs to the original join cost.
(NEVER add the join cost, just do the join cost at the beginning or else the clubs will never become the same cost.)
Club M1 M2 M3 M4 M5 M6 M7 M8 M9
Alpha: 60 65 70 75 80 85 90 95 100
Omega:20 30 40 50 60 70 80 90 100
If you look above, you realize that there is a time when they both cost the same.
Summary sentence:
After 9 months, the cost to belong to either fitness club would be $100.