document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=858020>Question 858020</A>: <I><SPAN STYLE=\"word-break: break-all;\"> S is the sum of the first 2n terms of a GP, if the sum of the alternate terms of the same gp is S/4, find the common ratio of the GP </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #516977 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=516977\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> S is the sum of the first 2n terms of a GP, if the sum of the alternate terms of the same gp is S/4, find the common ratio of the GP<BR>\n" );
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document.write( "S(2n) = a[(r^(2n)-1)/(r-1)] = S<BR>\n" );
document.write( "S(n) = a[(r^n-1)/(r-1)] = S/4<BR>\n" );
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document.write( "Divide S(2n)/S(n) to get:<BR>\n" );
document.write( "(r^(2n)-1)/(r^n-1) = 4<BR>\n" );
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document.write( "r^(2n)-1 = 4r^n - 4<BR>\n" );
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document.write( "(r^n)^2-1-4r^n+4 = 0<BR>\n" );
document.write( "(r^n)^2 - 4r^n + 3 = 0<BR>\n" );
document.write( "(r^n-1)(r^n-3) = 0<BR>\n" );
document.write( "r^n = 1 or r^n = 3<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "====================<BR>\n" );
document.write( " </SPAN>\n" );
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