Question 134973:  Given line segment AB with midpoint M(5,-1) and endpoint B(8,2), what are the coordinates of A? 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! Given line segment AB with midpoint M(5,-1) and endpoint B(8,2), what are the coordinates of A? 
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Draw the picture: 
Let the coordinates of A be (x,y) 
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Rule: The coordinates of the midpoint are the average of the corresponding 
coordinates of the end points. 
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(x+8)/2 = 5 
x+8 = 10 
x = 2 
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(y+2)/2 = -1 
y+2 = -2 
y = -4 
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Coordinates of A are (2,-4) 
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Cheers, 
Stan H. 
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