document.write( "Question 26927: 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 10 h what is the planes speed in still air? \n" ); document.write( "

Algebra.Com's Answer #14647 by Paul(988) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"720%2F%28x%2B30%29%2B720%2F%28x-30%29=10\"$
\n" ); document.write( "720[(x+30)+(x-30)]=10[(x+30)(x-30)]
\n" ); document.write( " $\"720%282x%29=10%28x%5E2-900%29\"$
\n" ); document.write( " $\"1440x-21600=10x%5E2-900\"$
\n" ); document.write( " $\"10x%5E2-1440x-9000=0\"$
\n" ); document.write( " $\"x%5E2-144-900=0\"$
\n" ); document.write( "Factor:
\n" ); document.write( "(x+6) and (x-150)
\n" ); document.write( "Remove the negative x=150\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Hence, the speed of the plane in still ari is 150mph.
\n" ); document.write( "Paul. \n" ); document.write( "

\n" );