document.write( "Question 995694: Please help me solve this word problem: (show all working out please, Thanks)\r
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document.write( "In a race over 4km Ryan ran at a constant speed. However, Sophie ran at the first 2 km at a speed of 1km/h more than Ryan and ran the second 2km at a speed of 1km/h less than Ryan. Who won the race? \n" );
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Algebra.Com's Answer #614386 by Theo(13342)![]() ![]() You can put this solution on YOUR website! ryan runs faster.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "here's my worksheet that confirms it for all ryan rates that are valid.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in this workbook:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x represnet ryans rate per kilometer.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the results are valid for all of ryan's rates greater than 1 kmph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "at 1 kmph, the results are not valid because there is a division by 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "at less than 1 kmph, the results are invalid because sophie's rates becomes negative.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the formulas used are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let x = ryan's rate.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "rate * time = distance\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "distance = 4 km.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "formula becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x * time = 4\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ryan's time = 4 / x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sophie's time is calculated as follows:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sophie's time for first 2 km is equal to 2 / (x+1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sophie's time for second 2 km is equal to 2 / (x-1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sophie's time for all 4 km is 2/(x+1) + 2/(x-1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "results are shown below:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "div/0 means the results are invalid because there has been a division by 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |