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Question 295832:  FIND AN EQUATION OF THE LINE CONTAINING THE GIVEN PAIR OF POINTS.
 
(-3,-1) (-9,-6) 
 Answer by Alan3354(69443)      (Show Source): 
You can  put this solution on YOUR website!  Given 2 points example.  
Find the equation of the line thru the points (2,1) and (3,5) 
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This is a 2 step process.  First find the slope of the line thru the points. 
slope, m = diffy/diffx 
m = (5-1)/(3-2) 
m = 4 
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Now use y = mx + b with either point to find b, the y-intercept. 
y = mx + b 
5 = 4*3 + b 
b = -7 
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y = mx + b 
y = 4x - 7 is the answer. 
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Another approach using determinants: 
|x y 1| 
|2 1 1| = 0 
|3 5 1| 
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x(1-5) - y(2-3) + 1(10-3) = 0 
-4x + y + 7 = 0 
y = 4x - 7 
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For further assistance, or to check your work, email me via the thank you note  
 or at MoralLoophole@aol.com 
 
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