document.write( "Question 903836: Please help me with this problem: A small airplane flies 810 miles from Los Angeles to Portland, Oregon, with an average speed of 270 miles per hour. An hour and a half after the plane leaves, a Boeing 747 leaves Los Angeles for Portland. Both planes arrive in Portland at the same time. What was the average speed of the 747? \n" ); document.write( "

Algebra.Com's Answer #548335 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
How much of a head start does the small
\n" ); document.write( "plane get?
\n" ); document.write( " $\"+d%5B1%5D+=+270%2A1.5+\"$
\n" ); document.write( " $\"+d%5B1%5D+=+405+\"$
\n" ); document.write( "-------------------
\n" ); document.write( "Start a stop watch when the 747 leaves
\n" ); document.write( "Let $\"+t+\"$ = the time on the stop watch
\n" ); document.write( "when both planes arrive in Portland
\n" ); document.write( " $\"+810+\"$ mi = the distance the 747 travels
\n" ); document.write( "during time $\"+t+\"$
\n" ); document.write( "Let $\"+s+\"$ = average speed of the 747
\n" ); document.write( "-------------------
\n" ); document.write( "747's equation:
\n" ); document.write( "(1) $\"+810+=+s%2At+\"$
\n" ); document.write( "Small plane's equation:
\n" ); document.write( " $\"+810+-+405+=+270t+\"$
\n" ); document.write( "(2) $\"+405+=+270t+\"$
\n" ); document.write( "-------------------
\n" ); document.write( "(2) $\"+t+=+1.5+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+810+=+s%2At+\"$
\n" ); document.write( "(1) $\"+s+=+810+%2F+1.5+\"$
\n" ); document.write( "(1) $\"+s+=+540+\"$
\n" ); document.write( "The average speed of the 747 is 540 mi/hr\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );