4. Tom decided to join Platinum Gym because of its new equipment. At the grand opening, the manager announced that 124 people had signed up for gym membership. As part of the grand opening event, the manager waived the registration fee for 50 random people.
(a) Write an expression to represent how much money Platinum Gym will make from the grand opening memberships. Simplify the expression and label any variables.
(b) After 6 months, how much money will Platinum Gym have made from the original 124 people who joined at the grand opening, assuming that all 124 people are still members? Show your work.