ANSWER

Step-by-step explanation
Let the number of hours the room is rented be h.
The college charges a reservation fee of $45 and an additional fee of $7.80 per hour.
The expression that represents these charges is:

The chemistry club wants to spend at most $115.20. This implies that they want to spend less than or equal to that amount.
In other words, the charges must be less than or equal to $115.20:

Solve for t by collecting like terms:

Therefore, they can rent the room for at most 9 hours.