document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1178529>Question 1178529</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write the first five terms of the geometric sequence. Find the common ratio and write the nth term of the sequence as a function of n.\r<BR>\n" );
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document.write( "a1 = 18, ak + 1 = −2/5ak\r<BR>\n" );
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document.write( "Common ratio=\r<BR>\n" );
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document.write( "an=<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 #807813 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=807813\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Using \"a1\" to denote the first term is poor form.  Use a(1) or a[1] or something like that.<br><BR>\n" );
document.write( "The form gets really bad when you try to write \"ak + 1\" for the (k+1)th term.  Use a(k+1) or a[k+1].<br><BR>\n" );
document.write( "The statement (in better form) \"a(k+1) = (-2/5)a(k)\" means each term is found by multiplying the previous term by (-2/5).  That tells you what the common ratio is.<br><BR>\n" );
document.write( "The n-th term of a geometric sequence is the first term, multiplied by the common ratio (n-1) times: a(n) = a(1)*r^(n-1).<br><BR>\n" );
document.write( "You can do the minimal amount of work to find the answers to your questions.<br><BR>\n" );
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