document.write( "Question 1051201: Sue rode her bike 21 miles. She began traveling at 12mph, the slowed down to 8mph in a hilly section. The trip took 2 hours. How long was she traveling at 12 mph and how long at 8 mph? \n" ); document.write( "

Algebra.Com's Answer #666786 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"R%5B1%5D%2At%5B1%5D%2BR%5B2%5D%2At%5B2%5D=21\"$
\n" ); document.write( " $\"12t%5B1%5D%2B8t%5B2%5D=21\"$
\n" ); document.write( "and
\n" ); document.write( " $\"t%5B1%5D%2Bt%5B2%5D=2\"$
\n" ); document.write( " $\"t%5B1%5D=2-t%5B2%5D\"$
\n" ); document.write( "Substituting,
\n" ); document.write( " $\"12%282-t%5B2%5D%29%2B8t%5B2%5D=21\"$
\n" ); document.write( " $\"24-12t%5B2%5D%2B8t%5B2%5D=21\"$
\n" ); document.write( " $\"-4t%5B2%5D=-3\"$
\n" ); document.write( " $\"t%5B2%5D=3%2F4\"$
\n" ); document.write( "and
\n" ); document.write( " $\"t%5B1%5D=2-3%2F4\"$
\n" ); document.write( " $\"t%5B1%5D=5%2F4\"$
\n" ); document.write( "45 minutes at 8 mph and 1 hr 15 min at 12 mph.
\n" ); document.write( " \n" ); document.write( "

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