I really need help with this!!!!!
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. Every day, his route takes him 22.5 miles against the current and back to his dock, and he needs to make the trip a total of 9 hours. He has a boat in mind but he can only test it on the lake with no current. How fast must the boat go on the lake in order to for it to serve the ferry operators needs?

Question

I really need help with this!!!!!
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. Every day, his route takes him 22.5 miles against the current and back to his dock, and he needs to make the trip a total of 9 hours. He has a boat in mind but he can only test it on the lake with no current. How fast must the boat go on the lake in order to for it to serve the ferry operators needs?

anonymous · Answer

let x be the speed of boat 
22.5/(x+6) + 22.5/(x-6) =

anonymous · Answer

okay.