document.write( "Question 1189956: Point B has coordinates ​(5​,2​). The​ x-coordinate of point A is −7. The distance between point A and point B is 15 units. What are the possible coordinates of point​ A?\r
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Algebra.Com's Answer #821468 by ikleyn(52908)\"\" \"About 
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\n" ); document.write( "Point B has coordinates ​(5​,2​). The​ x-coordinate of point A is −7.
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document.write( "The difference of x =-coordinates between points A and B is dx = 5 - (-7) = 5 + 7 = 12.\r\n" );
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document.write( "The difference of y-coordinates is unknown; let denote it dy.\r\n" );
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document.write( "Then you have this Pythagorean equation to find dy\r\n" );
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document.write( "    12^2 + (dy)^2 = 15^2,\r\n" );
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document.write( "which gives\r\n" );
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document.write( "    (dy)^2 = 15^2 - 12^2 = 225 - 144 = 81\r\n" );
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document.write( "hence, dy = +/- \"sqrt%2881%29\" = +/- 9.\r\n" );
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document.write( "It means that two possible coordinates of point A are  (-7,11)  and  (-7,-7).\r\n" );
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document.write( "    ( 11 = 2 + 9  is one possible y-coordinate;  -7 = 2 - 9  is another possible y-coordinate)\r\n" );
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