document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=262682>Question 262682</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A father is 30 years older than his son however he will be only thrice as old as the son after 5 years  what is father's present age ?\r<BR>\n" );
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document.write( "(a) 40 yrs    (b) 30 yrs      (c) 50 yrs      (d) none of these     </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #193489 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=193489\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> f = father's age.<BR>\n" );
document.write( "s = son's age.\r<BR>\n" );
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document.write( "the father is 30 years older than his son.\r<BR>\n" );
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document.write( "f = s + 30\r<BR>\n" );
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document.write( "in 5 years, the father will be 3 times as old as his son.\r<BR>\n" );
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document.write( "f + 5 = 3 * (s+5)\r<BR>\n" );
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document.write( "what is the father's age?\r<BR>\n" );
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document.write( "solve these 2 equations simultaneously to get your answer.\r<BR>\n" );
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document.write( "solve for f in terms of s in the first equation.   \r<BR>\n" );
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document.write( "this is already done because the equation states that:\r<BR>\n" );
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document.write( "f = s + 30\r<BR>\n" );
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document.write( "substitute for f in the second equation.\r<BR>\n" );
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document.write( "second equation is:\r<BR>\n" );
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document.write( "f + 5 = 3 * (s + 5)\r<BR>\n" );
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document.write( "equation becomes:\r<BR>\n" );
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document.write( "s + 30 + 5 = 3 * (s + 5)\r<BR>\n" );
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document.write( "simplify to get:\r<BR>\n" );
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document.write( "s + 35 = 3*s + 15\r<BR>\n" );
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document.write( "subtract s from both sides of this equation and subtract 15 from both sides of this equation to get:\r<BR>\n" );
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document.write( "20 = 2*s\r<BR>\n" );
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document.write( "divide both sides of this equation by 2 to get:\r<BR>\n" );
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document.write( "s = 20/2 = 10\r<BR>\n" );
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document.write( "from the first equation, we get:\r<BR>\n" );
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document.write( "f = s + 30 becomes f = 10 + 30 becomes f = 40\r<BR>\n" );
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document.write( "we have:\r<BR>\n" );
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document.write( "f = 40<BR>\n" );
document.write( "s = 10\r<BR>\n" );
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document.write( "substitute f = 40 and s = 10 in both original equations to see if they are true.\r<BR>\n" );
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document.write( "f = s + 30 becomes 40 = 10 + 30 becomes 40 = 40 which is true.\r<BR>\n" );
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document.write( "f + 5 = 3 * (s + 5) becomes 40 + 5 = 3 * (10 + 5) becomes 45 = 30 + 15 becomes 45 = 45 which is also true.\r<BR>\n" );
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document.write( "both equations are true confirming the values for f and s of 40 and 10 are good.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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