document.write( "Question 709493: Mary is 9 years older than Seth. In a year she will be 3 times as old as he is. How old are they? \n" ); document.write( "
Algebra.Com's Answer #436606 by Edwin McCravy(20056)\"\" \"About 
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Mary is 9 years older than Seth.
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document.write( "So Seth is x years old and Mary is x+9.\r\n" );
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\n" ); document.write( "In a year she will be 3 times as old as he is.
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document.write( "In 1 year she will be x+9 + 1, and he will be x + 1,\r\n" );
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document.write( "So x+9 + 1 equals 3 times x + 1\r\n" );
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document.write( "x+9+1 = 3(x+1)\r\n" );
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document.write( " x+10 = 3x+3\r\n" );
document.write( "  -2x = -7\r\n" );
document.write( "    x = \"3%261%2F2\"\r\n" );
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document.write( "So Seth is \"3%261%2F2\"  and Mary is 9 years older or \"12%261%2F2\".\r\n" );
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document.write( "Checking:\r\n" );
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document.write( "In one year she will be \"13%261%2F2\" and Seth will be \"4%261%2F2\"\r\n" );
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document.write( "So we need to check to ss if \"13%261%2F2\" is three times \"4%261%2F2\"\r\n" );
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document.write( "\"4%261%2F2%2A3+=+expr%289%2F2%29%2A3\" = \"27%2F2=13%261%2F2\"\r\n" );
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document.write( "So it checks.  That's a surprise because usually age problems \r\n" );
document.write( "have answers which are a whole number of years.  But not in this case.\r\n" );
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document.write( "Edwin
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