document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=192689>Question 192689</A>: <I><SPAN STYLE=\"word-break: break-all;\"> find three numbers in arithmetic progression whose sum is 21 and whose product is 180 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #144622 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=144622\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1st: x<BR>\n" );
document.write( "2nd: x + d<BR>\n" );
document.write( "3rd: x = 2d<BR>\n" );
document.write( "x + x + d + x + 2d = 21<BR>\n" );
document.write( "3x+3d = 21<BR>\n" );
document.write( "x + d = 7<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "x(x+d)(x+2d) = 180<BR>\n" );
document.write( "x(7)(x+2d) = 180<BR>\n" );
document.write( "7x^2 + 14xd - 180 = 0<BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "Solve the system using substitution: d = 7-x<BR>\n" );
document.write( "7x^2 + 14x(7-x) - 180 = 0<BR>\n" );
document.write( "7x^2 + 98x - 14x^2 - 180 = 0<BR>\n" );
document.write( "-7x^2 + 98x - 180 = 0<BR>\n" );
document.write( "x = 11.83 or x = 2.174..<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "Find d using d = 7-x<BR>\n" );
document.write( "==============================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );