document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=945704>Question 945704</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find a formula for the set of all points (x, y) for which the sum of the distances from (x, y) to (4, 0) and from (x, y) to (-4, 0) is 10.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #576863 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39620)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=576863\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You may be describing an ellipse.  Use the Distance Formula with your description.  The foci are (4,0) and (-4,0), and the needed sum of distances, 10.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%28x-4%29%5E2%2B%28y-0%29%5E2%29%2Bsqrt%28%28x-%28-4%29%29%5E2%2B%28y-0%29%5E2%29=10 ALIGN=MIDDLE  ALT=\"sqrt%28%28x-4%29%5E2%2B%28y-0%29%5E2%29%2Bsqrt%28%28x-%28-4%29%29%5E2%2B%28y-0%29%5E2%29=10\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Simplify that, and put into whatever form you need.  The center will be (0,0).\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%28x-4%29%5E2%2By%5E2%29%2Bsqrt%28%28x%2B4%29%5E2%2By%5E2%29=10 ALIGN=MIDDLE  ALT=\"sqrt%28%28x-4%29%5E2%2By%5E2%29%2Bsqrt%28%28x%2B4%29%5E2%2By%5E2%29=10\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%28x-4%29%5E2%2By%5E2%29=10-sqrt%28%28x%2B4%29%5E2%2By%5E2%29 ALIGN=MIDDLE  ALT=\"sqrt%28%28x-4%29%5E2%2By%5E2%29=10-sqrt%28%28x%2B4%29%5E2%2By%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-4%29%5E2=100-20sqrt%28%28x%2B4%29%5E2%2By%5E2%29%2B%28x%2B4%29%5E2 ALIGN=MIDDLE  ALT=\"%28x-4%29%5E2=100-20sqrt%28%28x%2B4%29%5E2%2By%5E2%29%2B%28x%2B4%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2-8x%2B16-%28x%5E2%2B8x%2B16%29-100=-20sqrt%28%28x%2B4%29%5E2%2By%5E2%29 ALIGN=MIDDLE  ALT=\"x%5E2-8x%2B16-%28x%5E2%2B8x%2B16%29-100=-20sqrt%28%28x%2B4%29%5E2%2By%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Not finished.  Square both sides and continue simplifying. </SPAN>\n" );
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