document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1145983>Question 1145983</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Four years ago, I was half as old as my father. Six years hence, I will be three fifths as old as he. How old I am now? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #767276 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=767276\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let x = your age and y = your father's age.\r<BR>\n" );
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document.write( "4 years ago, you were half as old as your father.<BR>\n" );
document.write( "the formula for that is x-4 = 1/2 * (y-4)\r<BR>\n" );
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document.write( "6 years from now, you will be 3/5 as old as your father.<BR>\n" );
document.write( "the formula for that is x+6 = 3/5 * (y+6)\r<BR>\n" );
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document.write( "you have two equations that need to be solved simultaneously.<BR>\n" );
document.write( "they are:\r<BR>\n" );
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document.write( "x-4 = 1/2 * (y-4)<BR>\n" );
document.write( "x+6 = 3/5 * (y+6)\r<BR>\n" );
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document.write( "add 4 to both sides of the first equation and subtract 6 from both sides of the second equation to get:\r<BR>\n" );
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document.write( "x = 1/2 * (y-4) + 4<BR>\n" );
document.write( "x = 3/5 * (y+6) - 6\r<BR>\n" );
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document.write( "simplify both equations to get:\r<BR>\n" );
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document.write( "x = 1/2 * y - 2 + 4 = 1/2 * y + 2<BR>\n" );
document.write( "x = 3/5 * y + 3/5 * 6 - 6 = 3/5 * y - 12/5\r<BR>\n" );
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document.write( "you get:\r<BR>\n" );
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document.write( "x = 1/2 * y + 2<BR>\n" );
document.write( "x = 3/5 * y - 12/5\r<BR>\n" );
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document.write( "put both equations under the common denominator of 10 to get:\r<BR>\n" );
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document.write( "x = 5/10 * y + 20/10<BR>\n" );
document.write( "x = 6/10 * y - 24/10\r<BR>\n" );
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document.write( "subtract the first equation from the second to get:\r<BR>\n" );
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document.write( "0 = 1/10 * y - 44/10\r<BR>\n" );
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document.write( "multiply both sides of this equation by 10 to get 0 = y - 44\r<BR>\n" );
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document.write( "add 44 to both sides of this equation and solve for y to get y = 44.\r<BR>\n" );
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document.write( "that's the current age of your father.\r<BR>\n" );
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document.write( "4 years ago, you were half the age of your father.<BR>\n" );
document.write( "that means that you were half of 40 = 20.\r<BR>\n" );
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document.write( "6 years from now, you will be 3/5 * the age of your father.<BR>\n" );
document.write( "your father will be 50 and you will be 3/5 * 50 = 30.\r<BR>\n" );
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document.write( "your current age has to be 24 because, 4 years ago you were 20, and 6 years from now, you will be 30.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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