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 .
Answer:
6+7=13
13+8=21
32+21=52
11+34=46
31+03=34
Step-by-step explanation:
im not sure in the 31+03
Graph will look like this if this is one of the options
we know that
A number is an inequality solution if the number satisfies the inequality
<u>Part 1)</u> 
rewrite the inequality

The answer Part 1) is the option D 
Because
satisfies the inequality
-----> is true
<u>Part 2)</u> 
The answer Part 2) is the option A 
Because
satisfies the inequality
-----> is true
<u>Part 3)</u> 
we're going to verify every case
<u>case A)</u> For 
substitute the value of x in the inequality

------> is true
therefore
The number
is a solution
<u>case B)</u> For 
substitute the value of x in the inequality

------> is not true
therefore
The number
is not a solution
<u>case C)</u> For 
substitute the value of x in the inequality

------> is not true
therefore
The number
is not a solution
<u>case D)</u> For 
substitute the value of x in the inequality

------> is not true
therefore
The number
is not a solution
therefore
The answer Part 3) is the option A 