document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=313023>Question 313023</A>: <I><SPAN STYLE=\"word-break: break-all;\"> For what values of the variable is the rational expression undefined?\r<BR>\n" );
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document.write( "    4<BR>\n" );
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document.write( "x2-9 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #223857 by </B><A HREF=/tutors/aboutme.mpl?userid=rapaljer><B>rapaljer(4671)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rapaljer><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/cgi-bin/show-face.mpl?user=rapaljer><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=223857\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rational expression is undefined if the denominator is zero.  In this case, the denominator is <BR>\n" );
document.write( "x^2 -9\r<BR>\n" );
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document.write( "Set this denominator equal to zero, factor the left side, and solve for x:<BR>\n" );
document.write( "(x-3)(x+3)=0<BR>\n" );
document.write( "x-3=0 or x+3=0<BR>\n" );
document.write( "x=3 or x=-3\r<BR>\n" );
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document.write( "Dr. Robert J. Rapalje, Retired </SPAN>\n" );
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