document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=946806>Question 946806</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The age of the father was 4 time and 2 times of his son in 1990 and 2008 respectively. Find the birth year of the son. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #577629 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=577629\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The age of the father was 4 time and 2 times of his son in 1990 and 2008 respectively. Find the birth year of the son.<BR>\n" );
document.write( " --------<BR>\n" );
document.write( " Equations:<BR>\n" );
document.write( " f = 4s<BR>\n" );
document.write( " f+18 = 2(s+18)<BR>\n" );
document.write( " ------<BR>\n" );
document.write( " Substitute for \"f\" and solve for \"s\"::<BR>\n" );
document.write( " 4s+18 = 2s+36<BR>\n" );
document.write( " 2s = 18<BR>\n" );
document.write( " s = 9 (son's age now)<BR>\n" );
document.write( " ----<BR>\n" );
document.write( " f = 4s<BR>\n" );
document.write( " f = 36 (father's age now)<BR>\n" );
document.write( " --------------------------<BR>\n" );
document.write( " Cheers,<BR>\n" );
document.write( " Stan H.<BR>\n" );
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document.write( "</TD></TR></TABLE>\n" );