document.write( "Question 1070839: it took Miguel 3.5 hours to drive from city a to city b. on his way back to city a, he increases his speed by 20 km per hour and it took him 3 hours. find the average speed for the whole journey \n" ); document.write( "

Algebra.Com's Answer #685836 by josgarithmetic(39620) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "              SPEED       TIME      DISTANCE\r\n" );
document.write( "A to B         r          3.5       d=(r)(3.5)\r\n" );
document.write( "B to A        r+20        3         d=(3)(r+20)\r\n" );
document.write( "Totals                   6.5       3.5r+3r+60\r\n" );
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\n" ); document.write( "\n" ); document.write( "-
\n" ); document.write( " $\"3.5r=3r%2B60\"$
\n" ); document.write( " $\"0.5r=60\"$
\n" ); document.write( " $\"highlight_green%28r=120%28kilometers%2Fhour%29%29\"$
\n" ); document.write( "-\r
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\n" ); document.write( "\n" ); document.write( "WHOLE JOURNEY, average speed:
\n" ); document.write( " $\"%286.5%2A120%2B60%29%2F6.5\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"highlight%28129%28kilometers%2Fhour%29%29\"$ \n" ); document.write( "

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