document.write( "Question 1109107: Jackie and Johnny are traveling from Seattle to San Diego. Jackie who is driving 80 mph caught up to Johnny who had a one hour Headstart and is driving 70 mph. How far were the two from their starting point when Jackie caught up to Johnny \n" ); document.write( "

Algebra.Com's Answer #724121 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Johnny's headstart in miles is:
\n" ); document.write( " $\"+d%5B1%5D+=+70%2A1+\"$
\n" ); document.write( " $\"+d%5B1%5D+=+70+\"$ mi
\n" ); document.write( "Start a stopwatch when Jackie leaves
\n" ); document.write( "Let $\"+t+\"$ = the time in hrs on the stopwatch
\n" ); document.write( "when Jackie catches up with Johnny
\n" ); document.write( "Let $\"+d+\"$ = the distance Jackie travels
\n" ); document.write( "until he catches up with Johnny
\n" ); document.write( "----------------------------------------
\n" ); document.write( "Johnny's equation:
\n" ); document.write( "(1) $\"+d+-+d%5B1%5D+=+70t+\"$
\n" ); document.write( "Jackie's equation:
\n" ); document.write( "(2) $\"+d+=+80t+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "(1) $\"+d+-+70+=+70t+\"$
\n" ); document.write( "Plug (2) into (1)
\n" ); document.write( "(1) $\"+80t+-+70+=+70t+\"$
\n" ); document.write( "(1) $\"+10t+=+70+\"$
\n" ); document.write( "(1) $\"+t+=+7+\"$ hrs
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+d+=+80%2A7+\"$
\n" ); document.write( "(2) $\"+d+=+560+\"$
\n" ); document.write( "Both were 560 mi from the starting point
\n" ); document.write( "----------------------------------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+d+-+70+=+70t+\"$
\n" ); document.write( "(1) $\"+d+=+70%2A7+%2B+70+\"$
\n" ); document.write( "(1) $\"+d+=+490+%2B+70+\"$
\n" ); document.write( "(1) $\"+d+=+560+\"$
\n" ); document.write( "OK \n" ); document.write( "

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