document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=902044>Question 902044</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Determine all values of c so that the lines cy+4x=9 and cy-5x=10 are perpendicular.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #547056 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=547056\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Using knowledge of standard form equation for a line, ax+by=k will have slope <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-a%2Fb ALIGN=MIDDLE  ALT=\"-a%2Fb\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "cy+4x=9 has slope <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-4%2Fc ALIGN=MIDDLE  ALT=\"-4%2Fc\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "cy-5x=10 has slope <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2Fc ALIGN=MIDDLE  ALT=\"5%2Fc\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "The two lines given to be perpendicular requires that the product of the slopes equals negative one, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28-%284%2Fc%29%2A%285%2Fc%29=-1%29 ALIGN=MIDDLE  ALT=\"highlight_green%28-%284%2Fc%29%2A%285%2Fc%29=-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.  Solve for c.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-20%2Fc%5E2=-1 ALIGN=MIDDLE  ALT=\"-20%2Fc%5E2=-1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20%2Fc%5E2=1 ALIGN=MIDDLE  ALT=\"20%2Fc%5E2=1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=20=c%5E2 ALIGN=MIDDLE  ALT=\"20=c%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c=0%2B-sqrt%284%2A5%29 ALIGN=MIDDLE  ALT=\"c=0%2B-sqrt%284%2A5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28c=0%2B-+2%2Asqrt%285%29%29 ALIGN=MIDDLE  ALT=\"highlight%28c=0%2B-+2%2Asqrt%285%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. </SPAN>\n" );
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