document.write( "Question 152310: 26.) The midpoint of the line segment joining a moving point to (6,0) is on the line y=x. Find the equation of its locus.
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\n" ); document.write( "\n" ); document.write( "This is a question that comes with the answer but I don't know how to solve for it. I tried using the midpoint formula but the answer is either x+y-6=0 or x-y-6=0. I don't know how to solve for this kind of problem...
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Algebra.Com's Answer #113242 by Edwin McCravy(20055)\"\" \"About 
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26.) The midpoint of the line segment joining a moving point to (6,0) is on the line y=x. Find the equation of its locus.
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document.write( "Graph the line \"y=x\":\r\n" );
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document.write( "\"graph%28400%2C400%2C-7%2C13%2C-7%2C13%2Cx%29\"\r\n" );
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document.write( "Call point (6,0) the point R.\r\n" );
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document.write( "Draw an arbitrary line from point R(6,0), crossing the\r\n" );
document.write( "line \"y=x\" at point M, and extending to P so that MP\r\n" );
document.write( "equals RM. making M the midpoint of RP.  P is the moving\r\n" );
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document.write( "Label the moving point P with the variable coordinates (x,y) \r\n" );
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document.write( "Since point M is the midpoint of the line segment RP, we use\r\n" );
document.write( "the midpoint formula to label M with the coordinates \r\n" );
document.write( "(\"%28x%2B6%29%2F2\",\"%28y%2B0%29%2F2\") or (\"%28x%2B6%29%2F2\",\"y%2F2\") \r\n" );
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document.write( "Now the point M(\"%28x%2B6%29%2F2\",\"y%2F2\") is on the line \"y=x\", so\r\n" );
document.write( "it must satisfy the equation \"y=x\", so we substitute that point \r\n" );
document.write( "into the equation \"y=x\" and we get:\r\n" );
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document.write( "\"y%2F2=%28x%2B6%29%2F2\"\r\n" );
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document.write( "Multiply both sides by 2:\r\n" );
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document.write( "\"y+=+x%2B6\"\r\n" );
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document.write( "That is equivalent to\r\n" );
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document.write( "\"x-y%2B6=0\"\r\n" );
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document.write( "To see the path of the moving point we draw the graph of\r\n" );
document.write( "\"x-y%2B6=0\" in green\r\n" );
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document.write( "Edwin
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