document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=169921>Question 169921</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Help, I just can't do it!\r<BR>\n" );
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document.write( "x is 3 years older than y<BR>\n" );
document.write( "z is twice as old as X<BR>\n" );
document.write( "4 years ago, x was twice as old as y<BR>\n" );
document.write( "   How old is x ? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125358 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=125358\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x is 3 years older than y<BR>\n" );
document.write( "z is twice as old as X<BR>\n" );
document.write( "4 years ago, x was twice as old as y<BR>\n" );
document.write( "How old is x ?<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "When you have three variables, you often need three equations:<BR>\n" );
document.write( "x = y+3<BR>\n" );
document.write( "z = 2x<BR>\n" );
document.write( "(x-4) = 2(y-4)<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "Rearrange:<BR>\n" );
document.write( "x  - y  +  0 = 3<BR>\n" );
document.write( "2x + 0  -  z = 0<BR>\n" );
document.write( "x  -2y  + 0  = -4<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "Solve by any method to get:<BR>\n" );
document.write( "x = 10<BR>\n" );
document.write( "y = 7<BR>\n" );
document.write( "z = 20<BR>\n" );
document.write( "==================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );