For what number of number of aerobics classes will the cost for members and nonmembers be the​ same?

Question

At a local fitness center, members pay a $6 membership fee and $3 for each aerobics class. Nonmembers pay $5 for each aerobics class. For what number of aerobics classes will the cost for members and nonmembers be the same?

Answer 1

Cost is a function of number of aerobics classes, a

 

members:  c(a) = 3a + 6

nonmembers:  c(a) = 5a

 

5a = 3a + 6

2a = 6

a = 3

 

The price is the same if they each take 3 aerobics classes ... $15