document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=918942>Question 918942</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The first term of an arithmetic progression is -8. The ratio of the 7th term to the 9th term is 5:8. Calculate the common difference. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #557367 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39618)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=557367\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5Bn%5D=-8%2B%28n-1%29d ALIGN=MIDDLE  ALT=\"a%5Bn%5D=-8%2B%28n-1%29d\"   DISABLED_style= \"max-width:90%; height:auto;\" >, index being n, common difference being d.\r<BR>\n" );
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document.write( "Ratio of seventh term to ninth term is 5:8,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-8%2B%287-1%29d%29%2F%28-8%2B%289-1%29d%29=5%2F8 ALIGN=MIDDLE  ALT=\"%28-8%2B%287-1%29d%29%2F%28-8%2B%289-1%29d%29=5%2F8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "That is the key equation to form; and solving it should be a comfortable process.  You basically want to determine the value of d, common difference between terms. </SPAN>\n" );
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