document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=692570>Question 692570</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An arithmetic series has a third term of 0. The sum of the first 15 terms is – 300. What is the first term? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #427052 by </B><A HREF=/tutors/aboutme.mpl?userid=mouk><B>mouk(232)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mouk><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=mouk><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=427052\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1st term = a, common difference = d\r<BR>\n" );
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document.write( "So terms are, a, a+d, a+2d, ...\r<BR>\n" );
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document.write( "3rd term = 0 means that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a%2B2d=0+ ALIGN=MIDDLE  ALT=\"+a%2B2d=0+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  ............ Eq (1)\r<BR>\n" );
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document.write( "so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%5Bn%5D=+%28n%2F2%29%282a+%2B+%28n-1%29d%29+ ALIGN=MIDDLE  ALT=\"+s%5Bn%5D=+%28n%2F2%29%282a+%2B+%28n-1%29d%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%5B15%5D+=+%2815%2F2%29%282a%2B14d%29+=+-300+ ALIGN=MIDDLE  ALT=\"+s%5B15%5D+=+%2815%2F2%29%282a%2B14d%29+=+-300+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%2815%2F2%29%282a%2B14d%29+=+-300+ ALIGN=MIDDLE  ALT=\"+%2815%2F2%29%282a%2B14d%29+=+-300+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2a%2B14d%29+=+-40+ ALIGN=MIDDLE  ALT=\"+2a%2B14d%29+=+-40+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  ............ Eq (2)\r<BR>\n" );
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document.write( "Eq (2) - 7 Eq (1) gives:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%282-7%29a+%2B%2814-14%29d=-40-0+ ALIGN=MIDDLE  ALT=\"+%282-7%29a+%2B%2814-14%29d=-40-0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-5a+=-40+ ALIGN=MIDDLE  ALT=\"+-5a+=-40+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a=8+ ALIGN=MIDDLE  ALT=\"+a=8+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, which is the first term\r<BR>\n" );
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document.write( "NB, If you need d then Eq (2) - 2 Eq (1) gives:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%282-2%29a+%2B%2814-4%29d=-40-0+ ALIGN=MIDDLE  ALT=\"+%282-2%29a+%2B%2814-4%29d=-40-0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10d=-40+ ALIGN=MIDDLE  ALT=\"+10d=-40+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d=-4+ ALIGN=MIDDLE  ALT=\"+d=-4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( " </SPAN>\n" );
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