document.write( "Question 1143969: Kirk could drive 300 miles in twice the time it took Spock to drive 240 miles. The speed of Spock was 30 mph greater than that of Kirk. What were the speed and times of both? \n" ); document.write( "

Algebra.Com's Answer #764922 by ikleyn(52866) $\"\"$ $\"About$

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document.write( "Let x be the Kirk' speed, in miles per hour.\r\n" );
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document.write( "Then the Spock' speed is (x+30) mph.\r\n" );
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document.write( "The time for Kirk is   hours.\r\n" );
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document.write( "The time for Spock is   mph.\r\n" );
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document.write( "The time equation is\r\n" );
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document.write( "     = .\r\n" );
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document.write( "From this equation,\r\n" );
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document.write( "    300*(x+30) = 480x,\r\n" );
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document.write( "    300x + 9000 = 480x\r\n" );
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document.write( "    9000 = 480x - 300x\r\n" );
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document.write( "    9000 = 180x\r\n" );
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document.write( "    x =  = 50.\r\n" );
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document.write( "ANSWER.  Kirk' speed is  50 mph;  Spock' speed is 50+30 = 80 mph.\r\n" );
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document.write( "                Kirk's time is   = 6 hours;  Spock' speed is   = 3 hours.\r\n" );
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