document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=474057>Question 474057</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the sum of:\r<BR>\n" );
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document.write( "S sub 21 for 23+20+17+14+...\r<BR>\n" );
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document.write( "Thank you in advance! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #325131 by </B><A HREF=/tutors/aboutme.mpl?userid=Tatiana_Stebko><B>Tatiana_Stebko(1539)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Tatiana_Stebko><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=Tatiana_Stebko><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=325131\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 23, 20, 17, 14, ... an arithmetic progression<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a1=23 ALIGN=MIDDLE  ALT=\"a1=23\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d=a2-a1=20-23=-3 ALIGN=MIDDLE  ALT=\"d=a2-a1=20-23=-3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Formula <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Sn=%28n%2F2%29%28a1%2Ban%29 ALIGN=MIDDLE  ALT=\"Sn=%28n%2F2%29%28a1%2Ban%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S21=%2821%2F2%29%28a1%2Ba21%29 ALIGN=MIDDLE  ALT=\"S21=%2821%2F2%29%28a1%2Ba21%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=an=a1%2B%28n-1%29d ALIGN=MIDDLE  ALT=\"an=a1%2B%28n-1%29d\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a21=23%2B%2821-1%29%2A%28-3%29=23-60=-37 ALIGN=MIDDLE  ALT=\"a21=23%2B%2821-1%29%2A%28-3%29=23-60=-37\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S21=%2821%2F2%29%2823%2B%28-37%29%29=-147 ALIGN=MIDDLE  ALT=\"S21=%2821%2F2%29%2823%2B%28-37%29%29=-147\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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