document.write( "Question 177643: Russ and Janet are running in the Apple Hill Fun Run. Russ runs at 7 mph, Janet runs at 5 mph. If they start at the same time, how long will it be before they are half a mile apart? show me step by step.. \n" ); document.write( "
Algebra.Com's Answer #132666 by Edwin McCravy(20056)\"\" \"About 
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Russ and Janet are running in the Apple Hill Fun Run. Russ runs at 7 mph, Janet runs at 5 mph. If they start at the same time, how long will it be before they are half a mile apart? show me step by step..
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\n" ); document.write( "You can do it in your head. But your teacher won't accept that. But I'll show you how to do it in your head anyway, then we'll do it by algebra. \r
\n" ); document.write( "\n" ); document.write( "In your head:
\n" ); document.write( "Their rate of separation is 7-5 or 2 miles an hour. So in 1 hour they would be 2 miles apart. In half an hour they would be 1 mile apart, so in half that time, or 15 minutes, they will be half a mile apart. Answer: 15 minutes.\r
\n" ); document.write( "\n" ); document.write( "But, of course, your teacher won't accept that. So,\r
\n" ); document.write( "\n" ); document.write( "By algebra:\r
\n" ); document.write( "\n" ); document.write( "Let t = the time in hours they both run before Russ is
\n" ); document.write( "ahead by \"1%2F2\" mile.
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document.write( "Make this DRT-chart\r\n" );
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document.write( "         Distance      Rate        Time\r\n" );
document.write( "Russ         \r\n" );
document.write( "Janet     \r\n" );
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document.write( "They both ran for t hours. So fill in t for both\r\n" );
document.write( "their times:\r\n" );
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document.write( "         Distance      Rate        Time\r\n" );
document.write( "Russ                                 t  \r\n" );
document.write( "Janet                                t\r\n" );
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document.write( "Now fill in 7 for Russ' rate and 5 for Janet's rate:\r\n" );
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document.write( "         Distance      Rate        Time\r\n" );
document.write( "Russ                     7           t  \r\n" );
document.write( "Janet                    5           t\r\n" );
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document.write( "Now use formula DISTANCE = RATE × TIME\r\n" );
document.write( "t fill in their distances:\r\n" );
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document.write( "         Distance      Rate        Time\r\n" );
document.write( "Russ       7t            7           t  \r\n" );
document.write( "Janet      5t            5           t\r\n" );
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document.write( "Now the difference between their distances \r\n" );
document.write( "must equal \"1%2F2\" mile:\r\n" );
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document.write( "Russ' distance MINUS Janet's distance = \"1%2F2\" a mile\r\n" );
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document.write( "So:\r\n" );
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document.write( "              7t - 5t = \"1%2F2\"\r\n" );
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document.write( "                   2t = \"1%2F2\"\r\n" );
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document.write( "Multiply both sides by 2 to clear of fractions:\r\n" );
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document.write( "                   4t = 1\r\n" );
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document.write( "Divide both sides by 4\r\n" );
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document.write( "                    t = \"1%2F4\"\r\n" );
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document.write( "That's \"1%2F4\" an hour or 15 minutes.\r\n" );
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document.write( "Edwin
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