document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=891648>Question 891648</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the age of the father is three more than 3 times the age of his son. 3 years hence father's age will be 10 years more than twice the age of the son. Determine their present ages </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #539969 by </B><A HREF=/tutors/aboutme.mpl?userid=tutor_paul><B>tutor_paul(519)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=tutor_paul><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=tutor_paul><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=539969\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> To solve this, first represent the words in terms of mathematical equations.<BR>\n" );
document.write( "Let F = Present Age of Father<BR>\n" );
document.write( "Let S = Present Age of Son<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "The first sentence is: \"the age of the father is three more than 3 times the age of his son.\"<BR>\n" );
document.write( "This can be represented as an equation as follows:<BR>\n" );
document.write( "Equation #1: F=3S<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "The second sentence is \"3 years hence father's age will be 10 years more than twice the age of the son\"<BR>\n" );
document.write( "This can be represented as an equation as follows:<BR>\n" );
document.write( "Equation #2: F+3=2S+10<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "So, now you have 2 equations and 2 unknowns. Anytime you can have a situation where you have as many equations as unknowns, you can solve the problem.<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "Substitute The expression for F in Equation #1 into Equation #2:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3S%2B3=2S%2B10 ALIGN=MIDDLE  ALT=\"3S%2B3=2S%2B10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Solve for S:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S%2B3=10 ALIGN=MIDDLE  ALT=\"S%2B3=10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28S=7%29 ALIGN=MIDDLE  ALT=\"highlight%28S=7%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "Now substitute this value of the son's age into Equation #1 to find the father's age:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=F=3%2A7 ALIGN=MIDDLE  ALT=\"F=3%2A7\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28F=21%29 ALIGN=MIDDLE  ALT=\"highlight%28F=21%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "=====================<BR>\n" );
document.write( "Good Luck,<BR>\n" );
document.write( "tutor_paul@yahoo.com<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );