The derivative of  in the direction of a vector
 in the direction of a vector  is
 is

With  , we get
, we get

and  ,
,

Then

 
        
             
        
        
        
Answer:
892.85 miles for 22 days
Step-by-step explanation:
 
        
             
        
        
        
Assuming your first equation is y = 5x+9, the equations describe lines that are coincident. 
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Multiplying the second equation by -1, it becomes y = 5x+9, the same as the first equation.
        
             
        
        
        
Answer:
Well, the first thing you must do is find the slope
(0,2) (1,-3) I am going to make x1= 0, y1=2, x2=1 and y2= -3
 
Now, I am going to use the formula for the slope, which is 
y2-y1/(x2-x1) 
[-3-2]/(1-0)= -5/1 or just -1
 
Next, I am going to use the point slope form, which is
y-y1=m(x-x1). m=5, x1=0, y1=2
y-2= -5(x-0)
y-2=-5x
 +2 +2
y= -5x+2 This is the slope intercept form.
we are done. I am glad to see that you are doing math on a Saturday night.. Good luck... Please rate my answer:)