document.write( "Question 1034622: A train travels 300km at a constant speed. If the speed had been 5km/h faster, the jounery would have taken 2 hours less. Find the speed of the train \n" ); document.write( "

Algebra.Com's Answer #649267 by ikleyn(52794) $\"\"$ $\"About$

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\n" ); document.write( "A train travels 300 km at a constant speed. If the speed had been 5 km/h faster, the joinery would have taken 2 hours less.
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document.write( "Your equation is \r\n" );
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document.write( " = 2.\r\n" );
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document.write( "where \"u\" is unknown train' speed.\r\n" );
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document.write( "To solve it, multiply both sides by u*(u+5) to get rid of the denominators. You will get\r\n" );
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document.write( "300*(u+5) - 300u = 2u*(u+5),   or\r\n" );
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document.write( " = ,   or\r\n" );
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document.write( " = .\r\n" );
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document.write( "Factor left side\r\n" );
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document.write( "(u+30)*(u-25) = 0.\r\n" );
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document.write( "The roots are u = 25 and u = -30.\r\n" );
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document.write( "Only positive u = 25 fits the condition.\r\n" );
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document.write( "Answer.  The train'speed is 25 .\r\n" );
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