document.write( "Question 923361: Michael Chan leaves a dock in his motorboat and travels at an average speed of 9 mph toward the Isle of Shoals, a small island off the coast of Massachusetts. Two hours later, a tour boat leaves the same dock and travels at an average speed of 18 mph toward the same island. How many hours after the tour boat leaves will Michael's boat be alongside the tour boat? \n" ); document.write( "

Algebra.Com's Answer #559993 by josmiceli(19441) $\"\"$ $\"About$

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Michael's head start is:
\n" ); document.write( " $\"+d%5B1%5D+=+9%2A2+\"$
\n" ); document.write( " $\"+d%5B1%5D+=+18+\"$ mi
\n" ); document.write( "-----------------
\n" ); document.write( "Start a stopwatch when the tour
\n" ); document.write( "boat leaves the dock
\n" ); document.write( "Let $\"+t+\"$ = time in hrs on stopwatch
\n" ); document.write( "when boats meet
\n" ); document.write( "Let $\"+d+\"$ = distance in mi from
\n" ); document.write( "dock to Isles of Shoals
\n" ); document.write( "-----------------
\n" ); document.write( "Michael's equation:
\n" ); document.write( "(1) $\"+d+-+18+=+9t+\"$
\n" ); document.write( "tour boat's equation:
\n" ); document.write( "(2) $\"+d+=+18t+\"$
\n" ); document.write( "-----------------
\n" ); document.write( "By substitution:
\n" ); document.write( "(1) $\"+18t+-+18+=+9t+\"$
\n" ); document.write( "(1) $\"+9t+=+18+\"$
\n" ); document.write( "(1) $\"+t+=+2+\"$ hrs
\n" ); document.write( "-----------------
\n" ); document.write( "The boats will meet in 2 hrs
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+d+-+18+=+9t+\"$
\n" ); document.write( "(1) $\"+d+-+18+=+9%2A2+\"$
\n" ); document.write( "(1) $\"+d+=+36+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+d+=+18t+\"$
\n" ); document.write( "(2) $\"+d+=+18%2A2+\"$
\n" ); document.write( "(2) $\"+d+=+36+\"$
\n" ); document.write( "OK
\n" ); document.write( "
\n" ); document.write( " \n" ); document.write( "

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