document.write( "Question 740364: Write two equations in two variables and solve.\r
\n" ); document.write( "\n" ); document.write( "A motorboat traveling with the current went 72 miles in 4 hours. Going against the current, it took 6 hours to travel the same distance. Find the rate of the boat in calm water and the rate of the current.
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Algebra.Com's Answer #451566 by ankor@dixie-net.com(22740)\"\" \"About 
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A motorboat traveling with the current went 72 miles in 4 hours.
\n" ); document.write( " Going against the current, it took 6 hours to travel the same distance.
\n" ); document.write( " Find the rate of the boat in calm water and the rate of the current.
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\n" ); document.write( "let s = the rate of the boat in calm water
\n" ); document.write( "let c = the rate of the current
\n" ); document.write( ":
\n" ); document.write( "Write a distance equation for each way
\n" ); document.write( "4(s+c) = 72
\n" ); document.write( "6(s-6) = 72
\n" ); document.write( "Simplify both equations, divide the 1st by 4 and the 2nd by 6, you have
\n" ); document.write( "s + c = 18
\n" ); document.write( "s - c = 12
\n" ); document.write( "-------------adding eliminates c, find s
\n" ); document.write( "2s = 30
\n" ); document.write( "s = 15 mph in calm water
\n" ); document.write( ":
\n" ); document.write( "I'll let you find the current rate, check solution is both original equations \n" ); document.write( "
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