document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=842985>Question 842985</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The sum of 16 terms of an A.P is -504 while the sum of the 9 terms is -126.<BR>\n" );
document.write( "Find the sum of 30 terms.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #514882 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=514882\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The sum of 16 terms of an A.P is -504 while the sum of the 9 terms is -126.<BR>\n" );
document.write( "Find the sum of 30 terms.\r<BR>\n" );
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document.write( "S = ½(2a + (n-1)d)n\r<BR>\n" );
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document.write( "-504 = ½(2a + 15d)16<BR>\n" );
document.write( "-126 = ½(2a + 8d)9<BR>\n" );
document.write( "a = 6,   d = -5<BR>\n" );
document.write( "S = ½(2*6 + -5(29))30<BR>\n" );
document.write( "S = -1995 for 30 terms </SPAN>\n" );
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