Answer:
4 Hours.
Explanation:
Since they charge $5 for every hour, we can use 5(x) as our first variable, x being the number of hours that he rented the paddle boar. Also, since they charge $8 up front, we have to subtract that from the total cost , so it would be $28 - $8. After this we divide the result ($20) by 5, since our coefficient is 5, and it costs $5 to rent it every hour. This results in 20/5, and comes out to 4 hours in total.