When x=1 y=13 when x=3 y=19 and when x=5 y=25 you just plug the numbers in for x and solve
        
                    
             
        
        
        
I'm pretty sure it's 114 miles.
        
                    
             
        
        
        
I am not able to see the picture
        
                    
             
        
        
        
In your situation you said that 
Putting those together, you'd have 
 because 
.
To evaluate the difference quotient, first find each piece on it's own:
 because 
 no matter what your x-value is.
 
So putting those together:
      
Remember that the difference quotient is basically finding the slope of something.  Since you were given that the slope is 0, the difference quotient should work out to match that.