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| Question 110439:  I need your help with this problem: Determine a relationship between the x and y values. Write an equation. If X is 1,2,3,4. And Y is -6,-5,-4,and -3.                                                                                                                                                                                                                                                If you do reply to me I greatly appriciate it for I have a test tomorro and I don't understand this question. I hope I wrote the question to where you can understand it easily. Thanks again for all your help!
 Found 2 solutions by  checkley71, edjones:
 Answer by checkley71(8403)
      (Show Source): Answer by edjones(8007)
      (Show Source): 
You can put this solution on YOUR website! (1,-6)(4,-3) 
 
 | Solved by pluggable solver: Finding the Equation of a Line |  | First lets find the slope through the points (  ,  ) and (  ,  ) 
 
 
  Start with the slope formula (note: (  ,  ) is the first point (  ,  ) and  (  ,  ) is the second point (  ,  )) 
 
 
  Plug in  ,  ,  ,  (these are the coordinates of given points) 
 
 
  Subtract the terms in the numerator  to get  .  Subtract the terms in the denominator  to get  
 
 
 
 
  Reduce 
 
 
 So the slope is
 
 
  
 
 
 
 
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 Now let's use the point-slope formula to find the equation of the line:
 
 
 
 
 ------Point-Slope Formula------
 
  where  is the slope, and (  ,  ) is one of the given points 
 
 So lets use the Point-Slope Formula to find the equation of the line
 
 
 
  Plug in  ,  , and  (these values are given) 
 
 
 
  Rewrite  as  
 
 
 
  Distribute  
 
 
  Multiply  and  to get  . Now reduce  to get  
 
  Subtract  from  both sides to isolate y 
 
 
  Combine like terms  and  to get   
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 Answer:
 
 
 
 So the equation of the line which goes through the points (
  ,  ) and (  ,  )  is:  
 
 The equation is now in
  form (which is slope-intercept form) where the slope is  and the y-intercept is  
 
 Notice if we graph the equation
  and plot the points (  ,  ) and (  ,  ),  we get this: (note: if you need help with graphing, check out this solver) 
 
 
  Graph of  through the points (  ,  ) and (  ,  ) 
 
 Notice how the two points lie on the line. This graphically verifies our answer.
 
 
 
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