document.write( "Question 1049677: A plane traveled 514.8 miles each way to Sydney and back. The trip there was with the wind. It took 5.5 hours. The trip back was into the wind. The trip back took 11 hours. What is the speed of the plane in still air?
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\n" ); document.write( "\n" ); document.write( "I got two equations out of this: 5.5x-5.5y=514.8, and 11x+11y=514.8. I solved the system to get 70.2 mph, and -23.4. Since speed in this sense can't be negative, does anybody know what I did wrong here? \n" ); document.write( "

Algebra.Com's Answer #665252 by josgarithmetic(39618) $\"\"$ $\"About$

You can put this solution on YOUR website!
Most likely a sign mistake, just as a guess. Possibly an interpretation mistake.\r
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\n" ); document.write( "\n" ); document.write( "I am using variable assignments:
\n" ); document.write( "x, speed in absence of wind
\n" ); document.write( "y, speed of the wind\r
\n" ); document.write( "\n" ); document.write( "\"Into\" the wind, means \"AGAINST\" the wind, making the actual speed slower than in absence of any wind; and notice how the longer travel time is given for \"against the wind\".\r
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document.write( "                SPEED           TIME       DISTANCE\r\n" );
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document.write( "WITHWIND        x+y              5.5       514.8\r\n" );
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document.write( "AGAINSTWIND     x-y             11         514.8\r\n" );
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\n" ); document.write( "\n" ); document.write( "You can find what your mistake was and should be able to form the needed equations and correctly solve. The management of the language was likely the mistake; and not the otherwise written symbolic number properties steps. \n" ); document.write( "

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