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? 
:
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 = {{{20/5}}}
x - 5 = 4
x = 4 + 5
x = 9 mph speed in still water