Algebra.Com's Answer #651216 by ikleyn(52788)![\"\"](\"/images/stars/stars-13.gif\")  
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document.write( "Hello, I need help with a question for homework for Algebra.\r
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document.write( "\"Melissa walks 3km to the house of a friend and returns home on a bike. She averages 4km per hour faster when cycling than when walking,
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document.write( "and the total time for both trips is two hours/ Find her walking speed, given that the formula for calculating time (in hours) is: t=d/s
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document.write( "where d=distance (in km)
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document.write( "and s=speed (in km/h)\"\r
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document.write( "I know that the walking speed is 1km/h but I cannot understand how to show the working algebraically.\r
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document.write( "If you could help I would be very grateful.\r
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document.write( "Kind Regards\r
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document.write( "Benjamin Austin
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document.write( "Let u be Melissa's walking speed, in  .\r\n" );
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document.write( "Then her biking speed is (u+4) .\r\n" );
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document.write( "The equation is\r\n" );
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document.write( " +  = 2\r\n" );
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document.write( "To solve it, multiply both sides by x*(x+4) to rid of denominators.\r\n" );
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document.write( "You will get a quadratic equation. Simplify and solve.\r\n" );
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document.write( "3(x+4) + 3x = 2x*(x+4),\r\n" );
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document.write( "6x + 4 =  ,\r\n" );
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document.write( " =  ,\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( "(x-2)*(x+1) = 0.\r\n" );
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document.write( "One root is x = -1. Disregard it as negative.\r\n" );
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document.write( "The other root is x = 2 {{km/h}}}.\r\n" );
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document.write( "Check if it is correct.\r\n" );
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document.write( "Answer. Melissa's walking speed is 2 . Her biking speed is 6 .\r\n" );
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