Answer:
The length of fencing will be 
Step-by-step explanation:
Step 1
Find the dimensions of the rectangle
we know that
The area of a rectangle is equal to

In this problem we have

so
-----> equation A
-----> equation B
Substitute equation B in equation A

square root both sides

Find the value of b
-----> 
step 2
Find the length of fencing
The perimeter of a rectangle is equal to

we have


substitute

Answer: −2x−7y=−4
Step-by-step explanation:
that is the full correct answer
The answer is the last one, the expression is already in the simplest form.
I think the answer is y=1/4x+2.
Hope that helps!!!