1/3 of the wall is covered in stone
        
             
        
        
        
The expressions for the width, W, and area, A, of the rectangle in terms of L are:
- W = 
 - L  - A = 

 
The expression for the perimeter of a rectangle is given as:
P = 2(L + W)
where L is its length and W its width
a. Given that the perimeter of the rectangle is 13 feet, then;
13 = 2(L + W)
divide through by 2
 = L + W
So that;
W = 
 - L
The required formula for the width as a function of L is: W = 
 - L
b. Area of a rectangle can be expressed as;
A = L * W
substitute the expression for width in that of area to have
A = L * ( 
 - L)
   = 
L - 
A = 
The expression for the area A is: A = 
Visit: brainly.com/question/10452031
 
        
             
        
        
        
Its basically 7 see there is nothing but the number 7 which means as to an expression its 7.
        
                    
             
        
        
        
The area of the square: 

where "a" is a length of side.
Therefore: