document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1209569>Question 1209569</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1 + 4 + 7 + 10 + ... + x = 287<BR>\n" );
document.write( "find x </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #849534 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39630)</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=849534\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <s>Needed to stay.  It was good;</s><BR>\n" );
document.write( "<s>x=1</s>\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<s>If find index went to 96, then x is 1.</s>\r<BR>\n" );
document.write( "\n" );
document.write( "Using formula, sum of arithmetic sequence,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2B%28n%2F2%29%281%2B1%2B3%28n-1%29%29%2Bx=287 ALIGN=MIDDLE  ALT=\"1%2B%28n%2F2%29%281%2B1%2B3%28n-1%29%29%2Bx=287\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Omitting steps, but leads to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%283%2F2%29n%5E2-n%2F2%2B1%2Bx=287 ALIGN=MIDDLE  ALT=\"%283%2F2%29n%5E2-n%2F2%2B1%2Bx=287\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "If subtract x from both sides, then\r<BR>\n" );
document.write( "\n" );
document.write( ".<BR>\n" );
document.write( ".<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3n%5E2-n-572%3C=0 ALIGN=MIDDLE  ALT=\"3n%5E2-n-572%3C=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "NOT FINISHED... </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );