Answer:

Explanation:
Given

per hour


Required
Derive an expression for the scenario
A tandem bike allows 2 individuals to ride on it at a time.
So, they will only pay for one rental fee because both can ride on it at the same time.
However, they need to get separate helmets.
For Helmets, they will spend:

For Rental, they will spend
for h hours.


Recall that they have just $80 to spend
So, substitute 80 for total

Hence, option C answers the question.