SOLUTION: A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft sq., what is the width of the path? I know t

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft sq., what is the width of the path? I know t      Log On


   

Question 35825This question is from textbook Beginning Algebra
: A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft sq., what is the width of the path?
I know that the answer is 10 ft., common sense told me this. I am sure that this has to be set up as a quadriadic equation, since that is what we are studying, I just don't know how to set up the problem. This question is from textbook Beginning Algebra

Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
Equation:
400=(30+2x)(20+2x)-(30*20)
400=600+4x^2+100x-600
4x^2+100x-400=0
x^2+25x-100=0
Can you solve from there?
Paul.