document.write( "Question 1071245: A motorist covered a journey of 690 km in 8 hours. He covered part of the journey at 90 km/h and the rest at 80 km/h.What was the distance that he covered at 80 km/h?
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Algebra.Com's Answer #686173 by josgarithmetic(39617) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "                      SPEED       TIME         DISTANCE\r\n" );
document.write( "First part             90           x            90x\r\n" );
document.write( "Second part            80           y            80y\r\n" );
document.write( "Totals                              8            690\r\n" );
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\n" ); document.write( "\n" ); document.write( " $\"system%28x%2By=8%2C90x%2B80y=690%29\"$ \r
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\n" ); document.write( "\n" ); document.write( " $\"x=8-y\"$
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\n" ); document.write( " $\"9x%2B8y=69\"$
\n" ); document.write( " $\"9%288-y%29%2B8y=69\"$
\n" ); document.write( " $\"72-9y%2B8y=69\"$
\n" ); document.write( " $\"-y=69-72\"$
\n" ); document.write( " $\"y=72-69\"$
\n" ); document.write( " $\"highlight%28y=3%29\"$ ---------time in hours at 80 km/h\r
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\n" ); document.write( "\n" ); document.write( "Distance done at 80 km/h ?
\n" ); document.write( " $\"80%2A3=highlight%28240%29\"$ , in kilometers \n" ); document.write( "

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