SOLUTION: A river flows at a speed of five miles per hour. A steamboat went upstream for five hours and stopped at a point 20 miles from where it started. What is the speed of the steamboat

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Question 697418: A river flows at a speed of five miles per hour. A steamboat went upstream for five hours and stopped at a point 20 miles from where it started. What is the speed of the steamboat in still waters?
20/(x+5)+20(x-5)=5
20(x+5)+20(x-5)=5x^2-125
40x=5x^2-125
8x=x^2-25
x^2-8x-25
After that, I don't know what to do?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A river flows at a speed of five miles per hour.
A steamboat went upstream for five hours and stopped at a point 20 miles from where it started.
What is the speed of the steamboat in still waters?
:
You don't need a quadratic equation to solve this
:
Let x = speed in still water
then
(x-5) = effective speed going upstream
:
Write a speed equation; speed = dist/time
:
x - 5 = 20%2F5
x - 5 = 4
x = 4 + 5
x = 9 mph speed in still water