document.write( "Question 1118486: Libby drive to work 1 hour. If she increases her average speed by 10 miles per hour, the trip takes 3/4 hour. Find the distance she drives to work \n" ); document.write( "

Algebra.Com's Answer #733818 by ikleyn(52781) $\"\"$ $\"About$

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document.write( "Let x be Libby's regular speed (in the first scenario), in miles per hour.\r\n" );
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document.write( "Then the distance to work is  distance = d = time*speed = 1 hour * x miles per hour = x miles.\r\n" );
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document.write( "This distance is equal to time*speed in the second scenario:\r\n" );
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document.write( "d = 0.75*(x+10)  miles.    (0.75 of an hour = 3/4 of an hour.)\r\n" );
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document.write( "Distance is the same, which gives you an equation\r\n" );
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document.write( "x = 0.75*(x+10),\r\n" );
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document.write( "Simplify and solve for x:\r\n" );
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document.write( "x = 0.75x + 7.5,\r\n" );
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document.write( "x - 0.75x = 7.5\r\n" );
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document.write( "0.25x = 7.5  ====>  x =  = 30 miles per hour.\r\n" );
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document.write( "Answer.  The distance to work is 30 miles.\r\n" );
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\n" ); document.write( "\n" ); document.write( "The solution by @addingup is incorrect.\r
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