document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=167513>Question 167513</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Anna made the following announcement:\r<BR>\n" );
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document.write( "In 7 years, I will be half my mother's age.  Thirteen years ago, she was 6 times as old as i was then.  \r<BR>\n" );
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document.write( "How old is Anna now? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #123394 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=123394\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In 7 years, I will be half my mother's age. Thirteen years ago, she was 6 times as old as i was then. <BR>\n" );
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document.write( "Let A = Anna's age<BR>\n" );
document.write( "and M = Mother's age<BR>\n" );
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document.write( "From:\"In 7 years, I will be half my mother's age\"<BR>\n" );
document.write( "A+7 = M/2 (equation 1)<BR>\n" );
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document.write( "From:\"Thirteen years ago, she was 6 times as old as i was then\"<BR>\n" );
document.write( "6(A-13) = M (equation 2)<BR>\n" );
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document.write( "Using the definition of M from equation 2, substitute it into equation 1 and solve for A:<BR>\n" );
document.write( "A+7 = M/2 <BR>\n" );
document.write( "A+7 = (6(A-13))/2<BR>\n" );
document.write( "A+7 = 3(A-13)<BR>\n" );
document.write( "A+7 = 3A - 39<BR>\n" );
document.write( "7 = 2A - 39<BR>\n" );
document.write( "46 = 2A<BR>\n" );
document.write( "23 years = A<BR>\n" );
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