For the first boat company, the rental is 35 + 7.25h
For the second company, the rental is 29 + 10.50h
You have to replace h with however long (in hours) you want to rent the boat and then you will find the better deal.
For one hour, Boat 1 is $42.25 and Boat 2 is $39.50, making Boat 2 the better deal. But for two hours, Boat 1 is $49.50 and Boat 2 is $56, making Boat 1 the better deal. I hope that helps!
EDIT:
I saw in the comments for another answer that you need to find a number of hours where the prices are the same. To do that, you just need to make the equations equal each other:
35 + 7.25h = 29 + 10.50h
Subtract 7.25h from each side
35 = 29 + 3.25h
Subtract 29 from each side
6 = 3.25h
Divide each side by 3.25
1.85 = h
Approximately one hour and 51 minutes will cost the same amount for both boat rental companies