Jeffrey purchased a card for $180 that
gives him 20 visits to a new gym and includes
a one-time fee for unlimited use of the sauna.
After 5 visits, Jeff has $123.75 left on the card,
and after 11 visits, he has S74.25 left on the
card. Write an equation that Jeffrey can use
to determine the cost of each visit and the fee
for the sauna use.