document.write( "Question 1109901: bobby left the space museum and drove south nancy left three hours later driving 42 km/h faster in an effort to catch up to him after two hours nancy finally caught up find bobby's average speed
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Algebra.Com's Answer #724871 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
Let \"+s+\" = Bobby's average speed
\n" ); document.write( "Bobby's head start is:
\n" ); document.write( "\"+d%5B1%5D+=+s%2A3+\" km
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\n" ); document.write( "Nancy's average speed is:
\n" ); document.write( "\"+s+%2B+42+\" km
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\n" ); document.write( "Let \"+d+\" = The distance Nancy traveled
\n" ); document.write( "until she caught up with Bobby
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\n" ); document.write( "Nancy's equation:
\n" ); document.write( "(1) \"+d+=+%28+s+%2B+42+%29%2A2+\"
\n" ); document.write( "Bobby's equation:
\n" ); document.write( "(2) \"+d+-+3s+=+s%2A2+\"
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\n" ); document.write( "Plug (1) into (2)
\n" ); document.write( "(2) \"+%28+s+%2B+42+%29%2A2+-+3s+=+2s+\"
\n" ); document.write( "(2) \"+2s+%2B+84+-3s+=+2s+\"
\n" ); document.write( "(2) \"+3s+=+84+\"
\n" ); document.write( "(2) \"+s+=+28+\" km/hr
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\n" ); document.write( "Bobby's average speed is 28 km/hr
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\n" ); document.write( "check answer:
\n" ); document.write( "(1) \"+d+=+%28+28+%2B+42+%29%2A2+\"
\n" ); document.write( "(1) \"+d+=+140+\" km
\n" ); document.write( "and
\n" ); document.write( "(2) \"+d+-+3%2A28+=+2%2A28+\"
\n" ); document.write( "(2) \"+d+-+84+=+56+\"
\n" ); document.write( "(2) \"+d+=+140+\" km
\n" ); document.write( "OK
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