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 .
<span>(4*10^2)(2*10^5)
= 8 x 10^7
hope it helps</span>
Answer:
General equation of line :
--1
Where m is the slope or unit rate
Table 1)
p d
1 3
2 6
4 12
d = Number of dollars (i.e.y axis)
p = number of pound(i.e. x axis)
First find the slope
First calculate the slope of given points
---A


Substitute values in A
Thus the unit rate is 3 dollars per pound.
So, It matches the box 1 (Refer the attached figure)
Equation 1 : 

Since p is the x coordinate and d is the y coordinate
On Comparing with 1

Thus the unit rate is
dollars per pound
So, It matches the box 2 (Refer the attached figure)
Equation 2 : 

Since p is the x coordinate and d is the y coordinate
On Comparing with 1

Thus the unit rate is 9 dollars per pound
So, It matches the box 3 (Refer the attached figure)
Table 2)
p d
1/9 1
1 9
2 18
d = Number of dollars (i.e.y axis)
p = number of pound(i.e. x axis)


Substitute values in A
Thus the unit rate is 9 dollars per pound
So, It matches the box 3 (Refer the attached figure)