document.write( "Question 1149181: Kristina went on a 220 mile trip to a soccer game. On the way back, due to road construction she had to drive 11 miles per hour slower. This made the trip take 1 hour longer. How fast did she drive to the soccer game? \n" ); document.write( "

Algebra.Com's Answer #770533 by ikleyn(52787) $\"\"$ $\"About$

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document.write( "Let \"x\" be the average rate driving \"to there\", in miles per hour.\r\n" );
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document.write( "The \"time\" equation is\r\n" );
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document.write( "     -  = 1\r\n" );
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document.write( "The first fraction on the left side is the time driving back;  the second fraction on the left is the time driving \"to there\";\r\n" );
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document.write( "the \"1\" on the right side is the given difference of the times.\r\n" );
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document.write( "Simplify the \"time\" equation step by step and solve for x:\r\n" );
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document.write( "    220*x - 220*(x-11) = x*(x-11)\r\n" );
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document.write( "    11*220            = x^2 - 11x\r\n" );
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document.write( "    x^2 - 11x - 2420 = 0\r\n" );
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document.write( "     =  = .\r\n" );
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document.write( "Only positive root makes sense\r\n" );
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document.write( "    x =  = 55.\r\n" );
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document.write( "ANSWER.  55 miles per hour.\r\n" );
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document.write( "CHECK.    -  =  -  = 5 - 4 = 1 hour.    ! Correct !\r\n" );
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\n" ); document.write( "\n" ); document.write( "Using \"time\" equation is the STANDARD method of solving such problems.\r
\n" ); document.write( "\n" ); document.write( "From this lesson, learn on how to write, how to use and how to solve a \"time\" equation.\r
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\n" ); document.write( "\n" ); document.write( "To see many other similar solved problems, look into the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Had a car move faster it would arrive sooner\r
\n" ); document.write( "\n" ); document.write( "    - How far do you live from school? \r
\n" ); document.write( "\n" ); document.write( "    - Earthquake waves \r
\n" ); document.write( "\n" ); document.write( "    - Time equation: HOW TO use, HOW TO write and HOW TO solve it \r
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