document.write( "Question 70733: A bicyclist rode into the country for 5 h. In returning, her
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document.write( "speed was 5 mi/h faster and the trip took 4 h. What was her speed each way? \n" );
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Algebra.Com's Answer #50498 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! We'll use the basic equation that says the distance (D) that you travel is equal to the rate \n" ); document.write( "or speed that you are going (R) times the Time (T) that you use. In equation form this is: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "On the trip out this bicyclist rode at some unknown rate (R) and she rode for 5 hours. \n" ); document.write( "Substituting these values into the equation results in: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "On the way back she boosted her rate by 5 mph. Therefore, her new rate was R+5. She rode \n" ); document.write( "for 4 hours. The equation that results is: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "But the distance she traveled out is the same distance that she traveled on the way back. \n" ); document.write( "This means that the left side of our two equations are equal. Because of this we can \n" ); document.write( "site the right side equal also. To be a little more conventional let's write R*5 as 5*R and \n" ); document.write( "(R+5)*4 as 4*(R+5). In equation form the equality of the right sides is: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Multiplying out the right side results in: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Subtract 4*R from both sides and the equation becomes: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "This means that she rode out at 20 mph and as a result her return rate, 5 mph faster, was \n" ); document.write( "25 mph. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to understand the problem a little better. \n" ); document.write( " |