document.write( "Question 640634: Mary leaves her home driving at 60 mph. One hour later, Jim leaves his work during the same route at 70 mph. How long will it take Jim to catch Mary? \n" ); document.write( "

Algebra.Com's Answer #403349 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Mary has a head start of $\"+60%2A1+=+60+\"$ mi
\n" ); document.write( "Start a stopwatch when Jim leaves
\n" ); document.write( "Let the time on the watch = $\"+t+\"$ hrs when
\n" ); document.write( "Jim catches Mary
\n" ); document.write( "Let $\"+d+\"$ = distance that Jim travels
\n" ); document.write( "to catch Mary
\n" ); document.write( "Mary's equation:
\n" ); document.write( "(1) $\"+d+-+60+=+60t+\"$
\n" ); document.write( "Jim's equation:
\n" ); document.write( "(2) $\"+d+=+70t+\"$
\n" ); document.write( "--------------
\n" ); document.write( "Substitute (2) into (1)
\n" ); document.write( "(1) $\"+70t+-+60+=+60t+\"$
\n" ); document.write( "(1) $\"+10t+=+60+\"$
\n" ); document.write( "(1) $\"+t+=+6+\"$
\n" ); document.write( "-----------
\n" ); document.write( "It will take 6 hrs for Jim to catch Mary
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+d+=+70t+\"$
\n" ); document.write( "(2) $\"+d+=+70%2A6+\"$
\n" ); document.write( "(2) $\"+d+=+420+\"$ mi
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+d+-+60+=+60%2A6+\"$
\n" ); document.write( "(1) $\"+d+=+360+%2B+60+\"$
\n" ); document.write( "(1) $\"+d+=+420+\"$ mi
\n" ); document.write( "OK \n" ); document.write( "

\n" );