document.write( "Question 631703: Hamma is training by running to a post across a field and then back. She runs the outward leg at 7m/s and the return leg at 5m/s.She takes 15.4 s.Find the distance to the post \n" ); document.write( "

Algebra.Com's Answer #397767 by josmiceli(19441) $\"\"$ $\"About$

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Call the distance in meters $\"+d+\"$
\n" ); document.write( "Call the outward time in sec $\"+t+\"$
\n" ); document.write( " $\"+d+=+7t+\"$
\n" ); document.write( " $\"+d+=+5+%2A+%2815.4+-+t%29++\"$
\n" ); document.write( "-----------------
\n" ); document.write( "By substitution
\n" ); document.write( " $\"+7t+=+5%2A%28+15.4+-+t+%29+\"$
\n" ); document.write( " $\"+7t+=+77+-+5t+\"$
\n" ); document.write( " $\"+12t+=+77+\"$
\n" ); document.write( " $\"+t+=+77%2F12+\"$ sec
\n" ); document.write( " $\"+t+=+6.4166+\"$ sec
\n" ); document.write( "and
\n" ); document.write( " $\"+d+=+7t+\"$
\n" ); document.write( " $\"+d+=+7%2A%2877%2F12%29+\"$
\n" ); document.write( " $\"+d+=+44.916+\"$ m
\n" ); document.write( "check answer:
\n" ); document.write( " $\"+44.916+=+5+%2A+%2815.4+-+t%29++\"$
\n" ); document.write( " $\"+44.916+=+77+-+5t+\"$
\n" ); document.write( " $\"+5t+=+77+-+44.916+\"$
\n" ); document.write( " $\"+5t+=+32.08333+\"$
\n" ); document.write( " $\"+t+=+6.4166+\"$
\n" ); document.write( "OK \n" ); document.write( "

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