David wants to build a rectangular fencing with the 5 identical parts for his animals. he has 780 feet of fencing to make it. what dimensions of each part will maximize the total enclosed area?

65 ft by 39 ft

Step-by-step explanation:

Let x ft be the length of each part and y ft be the width of each part. The total perimeter of all 5 parts is

The length of the large rectangle is 5y ft and the width of the large rectangle is x, so the total area is

From the first equation,

Substitute it into the area expression:

Find the derivative:

Equate it to 0:

Then

answer: i can’t tell you that

step-by-step explanation:

12cm

the answer is d