document.write( "Question 1173839: After sailing 13 mi, a sailor changed direction and increased the boat's speed by 4 mph. An additional 17 mi was sailed at the increased speed. The total sailing time was 2 h. Find the rate of the boat for the first 13 mi. \n" ); document.write( "

Algebra.Com's Answer #799157 by ikleyn(52810) $\"\"$ $\"About$

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document.write( "Let x be the slower rate, in miles per hour.\r\n" );
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document.write( "Then the faster rate is (x+4) mph.\r\n" );
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document.write( "The time equation is\r\n" );
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document.write( "     +  = 2   hours.    (*)\r\n" );
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document.write( "The solution/(the answer) is absolutely clear (obvious):  x = 13 mph.    ANSWER\r\n" );
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document.write( "CHECK.   +  = 1 = 1 = 2 hours.   ! Correct !\r\n" );
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\n" ); document.write( "\n" ); document.write( "Alternatively, you can solve equation (*) by reducing it to a quadratic equation, if you want.\r
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