document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1086516>Question 1086516</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write the following sum with summation notation: 2 - 12 + 72 - 432 + 2592 - 15552.\r<BR>\n" );
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document.write( "The index here is 1.  I do notice the pattern of multiplying -6 to get the following integers after 2, but I am having trouble finding f(i). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #700739 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=700739\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Use (-1)^a power to generate opposite signs for successive terms.<BR>\n" );
document.write( "(-1)^(n-1)*2*6^(n-1)<BR>\n" );
document.write( "n=1; 2<BR>\n" );
document.write( "n=2:-2*6^1<BR>\n" );
document.write( "n=3:+2*6^2<BR>\n" );
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