document.write( "Question 275490: A boat travels down a river for 4 h (traveling with the current), then turns around and takes 6 h to return (traveling against the current.) Let b be the rate of the boat, in miles per hour, in calm water and c be the rate of the current, in miles per hour. Suppose the distance traveled down the river by the boat is 72 mi. Write a system of equations that can be solved to find the rate of the boat in calm water and the rate of the current.
\n" ); document.write( "downstream _______ = 72
\n" ); document.write( "upstream ________ = 72
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #200977 by ankor@dixie-net.com(22740)\"\" \"About 
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A boat travels down a river for 4 h (traveling with the current), then turns around and takes 6 h to return (traveling against the current.)
\n" ); document.write( " Let b be the rate of the boat, in miles per hour, in calm water and c be the rate of the current, in miles per hour.
\n" ); document.write( " Suppose the distance traveled down the river by the boat is 72 mi.
\n" ); document.write( " Write a system of equations that can be solved to find the rate of the boat in calm water and the rate of the current.
\n" ); document.write( ":
\n" ); document.write( "(b - c) = speed upstream
\n" ); document.write( "(b + c) = speed down stream
\n" ); document.write( ":
\n" ); document.write( "Write a dist equation: dist = time * speed
\n" ); document.write( ":
\n" ); document.write( "4(b + c) = 72
\n" ); document.write( "6(b - c) = 72
\n" ); document.write( ":
\n" ); document.write( "Simplify both equations, divide the 1st by 4, divide the 2nd by 6, results
\n" ); document.write( "b + c = 18
\n" ); document.write( "b - c = 12
\n" ); document.write( "------------------Addition eliminates c, find b
\n" ); document.write( "2b = 30
\n" ); document.write( "b = 15 mph is the boat speed
\n" ); document.write( ":
\n" ); document.write( "I'll let you find the current speed (c) \n" ); document.write( "
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