document.write( "Question 1074383: During the first part of a trip a man travels 140km at a certain speed. He travels 63km on the second part at a speed 7km slower. The total time of the trip is 3 hours. How fast did he travel the first part of the trip? \n" ); document.write( "

Algebra.Com's Answer #689049 by ikleyn(52847) $\"\"$ $\"About$

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document.write( "Let \"r\" be the speed at the first part of the trip, in km/h.\r\n" );
document.write( "Then the speed at the second part is (r-7) km/h.\r\n" );
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document.write( "The \"time\" equation is \r\n" );
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document.write( " = 3.\r\n" );
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document.write( "Solve it for \"r\". For it, multiply both sides of the equation by r*(r-7). You will get\r\n" );
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document.write( "140*(r-7) + 63r = 3r*(r-7).\r\n" );
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document.write( "Simplify and solve this quadratic equation.\r\n" );
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