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the speed of the current in a river is 6 mph a ferry operator who works that part of the river is looking to buy a new boat for his business everyday his route takes him 22.5 miles against the current and back to his deck and he needs this trip in a total of 9 hours he has a ...
Thursday, January 24, 2013 at 7:58pm by lee
(22.5/r-6)+(22.5/r+6)=9 Multiply the equation by r^2-36. Resulting equation: 9r^2-45r-324=0 Simplify: r^2-5r-36=0 Factor: (r-9)(r+4) Answer: rate of ferry= 9mph
Thursday, January 24, 2013 at 7:58pm by Misha