SOLUTION: During rush hour, Fernando can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Fernando's rate on the side roads is 9 mi/h

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: During rush hour, Fernando can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Fernando's rate on the side roads is 9 mi/h      Log On


   

Question 85428: During rush hour, Fernando can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Fernando's rate on the side roads is 9 mi/h faster than his rate on the freeway, find his rate on the side roads.
Answer by scianci(186) About Me  (Show Source):
You can put this solution on YOUR website!
distance = (rate)(time)
rate = distance%2Ftime
20%2Ft = 15%2Ft + 9
Multiply by t:
t(20%2Ft = 15%2Ft + 9)
Cancel denominators:
20 = 15 + 9t
Subtract 15 from both sides:
5 = 9t
Divide both sides by 9:
5/9 = t
20%2F%285%2F9%29 = 20%7B9%2F5) = 36 MPH