document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=758581>Question 758581</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a geometric series, t1=3 and s3=21. Find the common ratio and the sum of the first 7 terms. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #461577 by </B><A HREF=/tutors/aboutme.mpl?userid=reviewermath><B>reviewermath(1029)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=reviewermath><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=reviewermath><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=461577\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Q:<BR>\n" );
document.write( "In a geometric series, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5B1%5D ALIGN=MIDDLE  ALT=\"t%5B1%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 3 and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S%5B3%5D ALIGN=MIDDLE  ALT=\"S%5B3%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 21. Find the common ratio and the sum of the first 7 terms.<BR>\n" );
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document.write( "A:<BR>\n" );
document.write( "3 + 3r + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3r%5E2 ALIGN=MIDDLE  ALT=\"3r%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 21<BR>\n" );
document.write( "1 + r + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2 ALIGN=MIDDLE  ALT=\"r%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 7<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2 ALIGN=MIDDLE  ALT=\"r%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > + r - 6 = 0<BR>\n" );
document.write( "(r + 3)(r - 2) = 0<BR>\n" );
document.write( "r = 2 OR -3<BR>\n" );
document.write( "The common ratio, r is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%282%29 ALIGN=MIDDLE  ALT=\"highlight%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28-3%29 ALIGN=MIDDLE  ALT=\"highlight%28-3%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "If the common ratio is 2, then the sum of the first 7 terms is:<BR>\n" );
document.write( "3 + 6 + 12 + 24 + 48 + 96 + 192 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28381%29 ALIGN=MIDDLE  ALT=\"highlight%28381%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "If the common ratio is -3, then the sum of the first 7 terms is:<BR>\n" );
document.write( "3 + (-9) + 27 + (-81) + 243 + (-729) + 2187 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%281641%29 ALIGN=MIDDLE  ALT=\"highlight%281641%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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