document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=323019>Question 323019</A>: <I><SPAN STYLE=\"word-break: break-all;\"> what are the numbers for which the rational expression is undefined? 22/-9y </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #231220 by </B><A HREF=/tutors/aboutme.mpl?userid=QH><B>QH(50)</B></A><img src=\"/images/stars/stars-07.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=QH><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=QH><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=231220\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> To make something 'undefined', the easy way to think about it is \"what numbers will put a zero in the denominator\", as anything divided by zero is undefined.\r<BR>\n" );
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document.write( "So what number(s) multiplied by -9 = 0?\r<BR>\n" );
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document.write( "You know immediately the answer is 0, but for more complex denominators or if you have to show work...\r<BR>\n" );
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document.write( "Set the denominator equal to zero<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-9y=0 ALIGN=MIDDLE  ALT=\"-9y=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-9y%29%2F-9=0%2F-9 ALIGN=MIDDLE  ALT=\"%28-9y%29%2F-9=0%2F-9\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=0 ALIGN=MIDDLE  ALT=\"y=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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