document.write( "Question 755969: Two trains are 351 miles apart, and their speeds differ by 21 mph. Find the speed of each train if they are traveling toward each other and will meet in 3 hours \n" ); document.write( "

Algebra.Com's Answer #459938 by josmiceli(19441) $\"\"$ $\"About$

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You can think of one train as standing still and the
\n" ); document.write( "other one approaching at the sum of their speeds.
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\n" ); document.write( "Let the speed of the slower train = $\"+s+\"$ mi/hr
\n" ); document.write( "The speed of the faster train = $\"+s+%2B+21+\"$ mi/hr
\n" ); document.write( "--------------
\n" ); document.write( " $\"+351+=+%28+s+%2B+s+%2B+21+%29%2A3+\"$
\n" ); document.write( " $\"+2s+%2B+21+=+117+\"$
\n" ); document.write( " $\"+2s+=+96+\"$
\n" ); document.write( " $\"+s+=+48+\"$
\n" ); document.write( " $\"+s+%2B+21+=+69+\"$
\n" ); document.write( "The speeds are 69 mi/hr and 48 mi/hr
\n" ); document.write( "check:
\n" ); document.write( "The faster train:
\n" ); document.write( " $\"+d%5B1%5D+=+69%2A3+\"$
\n" ); document.write( "The slower train:
\n" ); document.write( " $\"+d%5B2%5D+=+48%2A3+\"$
\n" ); document.write( "---------------
\n" ); document.write( " $\"+d%5B1%5D+=+207+\"$ mi
\n" ); document.write( "and
\n" ); document.write( " $\"+d%5B2%5D+=+144+\"$ mi
\n" ); document.write( " $\"+207+%2B+144+=+351+\"$
\n" ); document.write( "OK
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