Answer:
 
 
 at
 at 
Step-by-step explanation:
Given: The length of the rectangle is  and width of the rectangle is
 and width of the rectangle is 
To find: An expression that can be used to find the perimeter of the rectangle, and the perimeter when x is 4.
Solution: 
Here, Length is given as  
 
width of the rectangle is 
Let P represents the perimeter of the rectangle
We know that perimeter of a rectangle is 
So, we have



Therefore, the expression to find the perimeter is 
Now, we need to find the perimeter at  
 
On substituting  in
  in  we have,
 we have,




Hence, the perimeter is 62 units when x is 4.