PLEASE HELPP!!! MORE POINTS AND BRAINIEST MARK!

Mr. Gonzales would like to create a playground in his
backyard. He has 20 ft of fencing to enclose the play
area. Use this information for Items 10-13. S
10, Write a quadratic function in standard form that
models f(x), the total area of the playground in
square feet in terms of its width x in feet. Then
graph f(x).

11. Write the x- and y-intercepts of f(x) and interpret
them in terms of the problem.

12. Give the reasonable domain and range of f(x) as
inequalities, in interval notation, and in set
notation. Explain how you determined the
reasonable domain and range..

13. What is the maximum area for the playground?
What are the dimensions of the playground with
the maximum area?

Please, I need this tmr!