document.write( "Question 423288: An airplane flew for 3 hours with a tail wind of 18 kilometers per hour. The return flight against the wind took 4 hours. Find the rate of the plane in still air. \n" ); document.write( "

Algebra.Com's Answer #853208 by ikleyn(53427) $\"\"$ $\"About$

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\n" ); document.write( "An airplane flew for 3 hours with a tail wind of 18 kilometers per hour.
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\n" ); document.write( "\n" ); document.write( " The solution in the post by @mananth is irrelevant and inadequate to the problem.\r
\n" ); document.write( "\n" ); document.write( " I came to bring a correct solution.\r
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document.write( "Let x be the rate of the airplane in still air.\r\n" );
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document.write( "Then the rate of the airplane flying with    the wind is (x+18) km/h;\r\n" );
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document.write( "     the rate of the airplane flying against the wind is (x-18) km/h.\r\n" );
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document.write( "Write the distance equation, saying that the distance is the same with the wind\r\n" );
document.write( "and against the wind\r\n" );
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document.write( "    3(x+18) = 4(x-18)  kilometers.\r\n" );
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document.write( "Simplify this equation and find x\r\n" );
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document.write( "    3x + 54 = 4x - 72,\r\n" );
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document.write( "    54 + 72 = 4x - 3x,\r\n" );
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document.write( "       126  =    x.\r\n" );
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document.write( "?ANSWER.  The rate of the airplane in still air is 126 km/h.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved correctly.\r
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