document.write( "Question 175451: A passenger train travels 392 mi in the same time that it takes a freight train to
\n" ); document.write( "travel 322 mi. If the passenger train travels 20 mi/h faster than the freight train,
\n" ); document.write( "find the speed of each train. \n" ); document.write( "

Algebra.Com's Answer #130526 by josmiceli(19441) $\"\"$ $\"About$

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For each train:
\n" ); document.write( " $\"t+=+d%2Fv\"$
\n" ); document.write( "Given:
\n" ); document.write( "For passenger train:
\n" ); document.write( " $\"t+=+392%2Fv%5Bp%5D\"$
\n" ); document.write( "For freight train:
\n" ); document.write( " $\"t+=+322%2Fv%5Bf%5D\"$
\n" ); document.write( "(1) $\"392%2Fv%5Bp%5D+=+322%2Fv%5Bf%5D\"$
\n" ); document.write( "(2) $\"v%5Bp%5D+=+v%5Bf%5D+%2B+20\"$
\n" ); document.write( "Substitute for $\"v%5Bp%5D\"$ in (1)
\n" ); document.write( " $\"392%2F%28v%5Bf%5D+%2B+20%29+=+322%2Fv%5Bf%5D\"$
\n" ); document.write( "Multiply both sides by $\"v%5Bf%5D%2A%28v%5Bf%5D+%2B+20%29\"$
\n" ); document.write( " $\"392v%5Bf%5D+=+322%2A%28v%5Bf%5D+%2B+20%29\"$
\n" ); document.write( " $\"392v%5Bf%5D+=+322v%5Bf%5D+%2B+6440\"$
\n" ); document.write( " $\"70v%5Bf%5D+=+6440\"$
\n" ); document.write( " $\"v%5Bf%5D+=+92\"$ mi/hr
\n" ); document.write( "and, since
\n" ); document.write( "(2) $\"v%5Bp%5D+=+v%5Bf%5D+%2B+20\"$
\n" ); document.write( " $\"v%5Bp%5D+=+112\"$ mi/hr
\n" ); document.write( "check:
\n" ); document.write( "For passenger train:
\n" ); document.write( " $\"t+=+392%2Fv%5Bp%5D\"$
\n" ); document.write( " $\"t+=+392%2F112\"$
\n" ); document.write( " $\"t+=+3.5\"$ hrs
\n" ); document.write( "For freight train:
\n" ); document.write( " $\"t+=+322%2Fv%5Bf%5D\"$
\n" ); document.write( " $\"t+=+322%2F92\"$
\n" ); document.write( " $\"t+=+3.5\"$ hrs
\n" ); document.write( "OK \n" ); document.write( "

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