SOLUTION: Sue rowed her boat across and back lake bend in 3 hours. if her returning rate was 2mph less than the going rate, and if the distance each way was 7 miles find her rate going.
w
Question 290323: Sue rowed her boat across and back lake bend in 3 hours. if her returning rate was 2mph less than the going rate, and if the distance each way was 7 miles find her rate going.
would it be 7 over x plus 7 over x-2=3?
I have to solve it using the quadratic formula. Thanks Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Sue rowed her boat across and back lake bend in 3 hours.
if her returning rate was 2mph less than the going rate, and if the distance each way was 7 miles find her rate going.
:
Yes, it could be: + = 3
Multiply by x(x-2), results
7(x-2) + 7x = 3x(x-2)
:
7x - 14 + 7x = 3x^2 - 6x
:
14x - 14 = 3x^2 - 6x
combine like terms to have a quadratic equation
0 = 3x^2 - 6x - 14x + 14
:
3x^2 - 20x + 14 = 0
:
the quadratic formula
In this problem a=3; b=-20; c=14
:
:
Two solutions
x =
x = 5.87
and
x =
x = .795
:
The reasonable solution: x = 5.87 mph, her rate going
:
:
Check solution by finding the times coming and going
7/5.87 = 1.19, going
7/3.87 = 1.81, returning
----------------
total = 3 hrs
