Your answer would be “a”.
In order to receive a positive solution in the following equation, you must include a double negative to have them cancel each other out and come up with a positive value. Sorry if this is confusing it’s easier to explain this process in person rather than online but I hope this helps anyways :)
Answer:
it will cost 34.25 to rent a bike for 6 hours
In case you're not already aware, the expression 
is called the "difference quotient" and represents the average rate of change of a function 
over an interval ![[x,x+h]](https://tex.z-dn.net/?f=%5Bx%2Cx%2Bh%5D)
.
For the function 
, by substituting 
we get
Then the difference quotient is
where the last equality holds as long as 
.
