document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1064497>Question 1064497</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the value of x?<BR>\n" );
document.write( "https://static.k12.com/nextgen_media/assets/1543530-IM2_141011_021105.jpg </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #679552 by </B><A HREF=/tutors/aboutme.mpl?userid=math_helper><B>math_helper(2461)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_helper><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=math_helper><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=679552\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The smaller (upper) triangle has sides that are proportional to the larger (outermost) triangle.  Let's set up a proportion:\r<BR>\n" );
document.write( "\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%283x-20%29%2F%28%283x-20%29%2B56%29+=+%289%2F%289%2B72%29%29+ ALIGN=MIDDLE  ALT=\"+%283x-20%29%2F%28%283x-20%29%2B56%29+=+%289%2F%289%2B72%29%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( " Noting that   <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9%2F%289%2B72%29+=+9%2F81+=+1%2F9+ ALIGN=MIDDLE  ALT=\"+9%2F%289%2B72%29+=+9%2F81+=+1%2F9+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( " Let's us simplify to:<BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=++%283x-20%29+%2F+%283x%2B36%29+=+1%2F9+ ALIGN=MIDDLE  ALT=\"++%283x-20%29+%2F+%283x%2B36%29+=+1%2F9+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=++9%2A%283x-20%29+=+3x%2B36+ ALIGN=MIDDLE  ALT=\"++9%2A%283x-20%29+=+3x%2B36+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+++27x+-+180+=+3x%2B36+ ALIGN=MIDDLE  ALT=\"+++27x+-+180+=+3x%2B36+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "     <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=++24x+=+216+ ALIGN=MIDDLE  ALT=\"++24x+=+216+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=++x+=+216%2F24+=+highlight%289%29+ ALIGN=MIDDLE  ALT=\"++x+=+216%2F24+=+highlight%289%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "—<BR>\n" );
document.write( "Check:   (3(9)-20) / (3(9)-20+56) = 7/63 = 1/9  (= 9/81 = 9/(72+9), so its ok) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );