Here it is given that the width is x ft and total length of the fence is 2400 ft .
Let the length be y ft
So we have

Let A represents area, and area is the product of length and width .
So we get

Substituting the value of y, we will get

Second part
The area is maximum at the vertex, and vertex is

And

And that's the required dimensions .
I think it’s b.5. Hope this helps. :)
Answer:
#5A=6
5B=4
Step-by-step explanation:
(-4,7) answer A
if u reflect it over y axis