SOLUTION: Lucy Steele drove 72 miles to a meeting and returned by the same route. She ddrove 5 miles per hours slower and the trip took 12 minutes longer. What was her speed on the way to th

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Lucy Steele drove 72 miles to a meeting and returned by the same route. She ddrove 5 miles per hours slower and the trip took 12 minutes longer. What was her speed on the way to th      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 923025: Lucy Steele drove 72 miles to a meeting and returned by the same route. She ddrove 5 miles per hours slower and the trip took 12 minutes longer. What was her speed on the way to the meaning

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Lucy Steele drove 72 miles to a meeting and returned by the same route. She ddrove 5 miles per hours slower and the trip took 12 minutes longer. What was her speed on the way to the meaning
------------------------------------------
Faster drive DATA:
distance = 72 miles ; rate = x mph ; time = 72/x hrs
----------------
Slower Drive DATA:
distance = 72 miles ; rate = x-5 mph ; time = 72/(x-5) hrs
-------
Note:: 12 minutes = (1/5)hr
-----
Equation::
slower time - faster time = 1/5 hr
------
72/(x-5) - 72/x = 1/5
-------
5x*72 - 5(x-5)72 = x(x-5)
-----------------------------
25*72 = x(x-5)
------
x^2 - 5x - 25*72 = 0
----
Ans: x = 45 (faster speed)
x-5 = 40 slower speed
------------------
Cheers,
Stan H.