document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=728206>Question 728206</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Mr. Klinker is 35 and his daughter is 10.  In how many years will Mr. Klinker be twice as old as his daughter?\r<BR>\n" );
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document.write( "What mathematical concept is this and how do you set it up, please? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #445352 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=445352\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Mr. Klinker is 35 and his daughter is 10.  In how many years will Mr. Klinker be twice as old as his daughter?\r<BR>\n" );
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document.write( "What mathematical concept is this and how do you set it up, please?<BR>\n" );
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document.write( "The difference in age is, and always will be, 25 years.<BR>\n" );
document.write( "If he's 2x her age, --> 50 & 25.<BR>\n" );
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document.write( "The hard way:<BR>\n" );
document.write( "k = his age<BR>\n" );
document.write( "d = her age<BR>\n" );
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document.write( "35 + x = (10 + x)*2<BR>\n" );
document.write( "35 + x = 20 + 2x<BR>\n" );
document.write( "x = 15<BR>\n" );
document.write( "--> in 15 years<BR>\n" );
document.write( "same answer<BR>\n" );
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