Answer:
20 times
Explanation:
Let's form two expressions relating the amount you would pay in each scenario:
• If we consider
to be the number of times you use the pool, and you pay $2 each time with a $75 membership fee, then
total cost =

• If you pay $5 each time with a $15 membership fee, then
total cost =

According to the question, the two costs should be equal.
∴

Now we have to solve for
:
⇒
[subtracting
from each side]
⇒

⇒
[subtract 15 from each side]
⇒

∴

This means that you must visit the pool 20 times for the costs to be equal.