document.write( "Question 46935This question is from textbook Beginning Algebra
\n" ); document.write( ": I don't usually have trouble with these, but even with my little chart, I'm getting confused on how set up the problem.\r
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\n" ); document.write( "\n" ); document.write( "A plane flies 720 mi against a steady 30 mi/h headwind and then returns to the same point with the wind. If the entire trip takes 10h, what is the plane's speed in still air? \n" ); document.write( "
Algebra.Com's Answer #31092 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
A plane flies 720 mi against a steady 30 mi/h headwind and then returns to the same point with the wind. If the entire trip takes 10h, what is the plane's speed in still air?\r
\n" ); document.write( "\n" ); document.write( "WITH THE WIND DATA:
\n" ); document.write( "distance =720 mi ; rate= plane speed +30 ; time =d/r= 720/(p+30)\r
\n" ); document.write( "\n" ); document.write( "AGAINST THE WIND DATA:
\n" ); document.write( "distance = 720 mi ; rate = plane speed -30; time = d/r = 720/(p-30)\r
\n" ); document.write( "\n" ); document.write( "EQUATION:
\n" ); document.write( "720/(p+30) + 720/(p-30) = 10\r
\n" ); document.write( "\n" ); document.write( "72/(p+30) + 72/(p-30) = 1
\n" ); document.write( "72p-72*30+72p+72*30 = (p+30)(p-30)
\n" ); document.write( "144p=p^2-900
\n" ); document.write( "p^2-144p-900=0
\n" ); document.write( "(p-150)(P+6)=0
\n" ); document.write( "p=150 mph. ( The plane's speed in still air is 150 mph)
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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