document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=404734>Question 404734</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In square ABCD, diagonal AC has a slope of -2/5.  what is the slope of diagonal BD? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #286015 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20849)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=286015\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the two diagonals in a square are at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=right ALIGN=MIDDLE  ALT=\"right\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+angles ALIGN=MIDDLE  ALT=\"+angles\"   DISABLED_style= \"max-width:90%; height:auto;\" > to each other;\r<BR>\n" );
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document.write( " hence if one diagonal has a <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=slope+=+-+%28+2%2F5+%29 ALIGN=MIDDLE  ALT=\"slope+=+-+%28+2%2F5+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, the other must have <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=slope+=+%2B+%28+5%2F2+%29 ALIGN=MIDDLE  ALT=\"slope+=+%2B+%28+5%2F2+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Explanation:\r<BR>\n" );
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document.write( " We know that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=if+ ALIGN=MIDDLE  ALT=\"if+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=two+ ALIGN=MIDDLE  ALT=\"two+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=lines ALIGN=MIDDLE  ALT=\"lines\"   DISABLED_style= \"max-width:90%; height:auto;\" > are at right angles to each other, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=product ALIGN=MIDDLE  ALT=\"product\"   DISABLED_style= \"max-width:90%; height:auto;\" > of their slopes <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=must ALIGN=MIDDLE  ALT=\"must\"   DISABLED_style= \"max-width:90%; height:auto;\" > be equal to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28+-+1+%29 ALIGN=MIDDLE  ALT=\"%28+-+1+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. \r<BR>\n" );
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document.write( "check:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-%282%2F5%29%28+5%2F2+%29=%28-%282%2A5%29%29%2F%285%2A2%29+=+-10%2F10=-1 ALIGN=MIDDLE  ALT=\"-%282%2F5%29%28+5%2F2+%29=%28-%282%2A5%29%29%2F%285%2A2%29+=+-10%2F10=-1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "hence slope of the other diagonal <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+BD+=+5%2F2 ALIGN=MIDDLE  ALT=\"+BD+=+5%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " </SPAN>\n" );
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