document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=855000>Question 855000</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The sum of the first 25 terms of an arithmetic series with a common difference of 5 is 1300. Find the first term of the series.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #515005 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=515005\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The sum of the first 25 terms of an arithmetic series with a common difference of 5 is 1300. Find the first term of the series. <BR>\n" );
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document.write( "1st term: a(1)<BR>\n" );
document.write( "25th term: a(1)+24d = a(1) + 24*5 = a(1)+120<BR>\n" );
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document.write( "Sum Formula: S(n) = (n/2)(a(1)+last term))<BR>\n" );
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document.write( "1300 = (25/2)(a(1)+a(1)+120))<BR>\n" );
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document.write( "2600 = 25[2(a(1))+120<BR>\n" );
document.write( "104 = 2*a(1) + 120<BR>\n" );
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document.write( "2*a(1) = -16<BR>\n" );
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document.write( "a(1) = -8<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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