document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=62371>Question 62371</A>: <I><SPAN STYLE=\"word-break: break-all;\"> John's present age is three-fourths of Sally's present age. In five years, John's age will be four-fifths of Sarah's age at that time. What are the present ages of John and Sally? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #43072 by </B><A HREF=/tutors/aboutme.mpl?userid=joyofmath><B>joyofmath(189)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=joyofmath><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=43072\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <b>John's present age is three-fourths of Sally's present age. In five years, John's age will be four-fifths of Sarah's age at that time. What are the present ages of John and Sally?</b>\r<BR>\n" );
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document.write( "The two equations are:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=J=%283%2F4%29S ALIGN=MIDDLE  ALT=\"J=%283%2F4%29S\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=J%2B5=%284%2F5%29%28S%2B5%29 ALIGN=MIDDLE  ALT=\"J%2B5=%284%2F5%29%28S%2B5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "Replace J with (3/4)S in the 2nd equation:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%283%2F4%29S%2B5=%284%2F5%29%28S%2B5%29 ALIGN=MIDDLE  ALT=\"%283%2F4%29S%2B5=%284%2F5%29%28S%2B5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "Multiply both sides of the equation by 20 to get rid of the fractions:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15S%2B100=16%28S%2B5%29 ALIGN=MIDDLE  ALT=\"15S%2B100=16%28S%2B5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "Or, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15S%2B100=16S%2B80 ALIGN=MIDDLE  ALT=\"15S%2B100=16S%2B80\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "Or, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=100=S%2B80 ALIGN=MIDDLE  ALT=\"100=S%2B80\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "So, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S=20 ALIGN=MIDDLE  ALT=\"S=20\"   DISABLED_style= \"max-width:90%; height:auto;\" >. <BR>\n" );
document.write( "Sally is 20 years old. John is 3/4 of Sally's age so John is 15.\r<BR>\n" );
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document.write( "Verification:<BR>\n" );
document.write( "In 5 years Sally will be 25 and John will be 20 which is indeed four-fifth's of Sally's age in 5 years. </SPAN>\n" );
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