document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=42674>Question 42674</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Which equations is undefined\r<BR>\n" );
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document.write( "A) y=4\r<BR>\n" );
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document.write( "B) y=-2x\r<BR>\n" );
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document.write( "C) x=4\r<BR>\n" );
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document.write( "D) y=x+4 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #27781 by </B><A HREF=/tutors/aboutme.mpl?userid=Nate><B>Nate(3500)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Nate><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=27781\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Vertical lines are undefined:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+4 ALIGN=MIDDLE  ALT=\"x+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "take two points: (4,0) and (4,2)<BR>\n" );
document.write( "M = (y2 - y1)/(x2 - x1) = (0 - 2)/(4 - 4) = -2/0 undefined<BR>\n" );
document.write( "(C) is your answer. </SPAN>\n" );
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