document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=239836>Question 239836</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a man is now four times as old as his son and in four years from now, the product of their ages will be 520. Find their ages now. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #175896 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley77><B>checkley77(12844)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley77><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=175896\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> LET THE MAN'S AGE=4X<BR>\n" );
document.write( "LET THE SON'S AGE-X<BR>\n" );
document.write( "(4X+4)(X+4)=520<BR>\n" );
document.write( "4X^2+4X+16X+16=520<BR>\n" );
document.write( "4X^2+20X+16-520=0<BR>\n" );
document.write( "4X^2+20X-504=0<BR>\n" );
document.write( "4(X^2+5X-126)=0<BR>\n" );
document.write( "4(X-9)(X+14)=0<BR>\n" );
document.write( "X-9=0<BR>\n" );
document.write( "X=9 AGE OF THE SON.<BR>\n" );
document.write( "4*9=36 AGE OF THE DAD.<BR>\n" );
document.write( "PROOF:<BR>\n" );
document.write( "(4*9+4)(9+4)=520<BR>\n" );
document.write( "(36+4)(13)=520<BR>\n" );
document.write( "40*13=520<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );