document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1007932>Question 1007932</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If the 4th term of a geometric sequence is 15 and the 7th term is 405, find the common ratio, and the first term </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #805106 by </B><A HREF=/tutors/aboutme.mpl?userid=CubeyThePenguin><B>CubeyThePenguin(3113)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=CubeyThePenguin><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=CubeyThePenguin><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=805106\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a = first term, r = third term\r<BR>\n" );
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document.write( "ar^3 = 15<BR>\n" );
document.write( "ar^7 = 405\r<BR>\n" );
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document.write( "Divide equation 2 by equation 1:\r<BR>\n" );
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document.write( "(ar^7)/(ar^3) = 405/5 = 81 = r^4\r<BR>\n" );
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document.write( "r = 3 or -3, so a = 15/27 = 5/9.\r<BR>\n" );
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