12.
1: n•n= n^2
2: n•(-2)= -2n
3: 2•n= 2n
4: 2•(-2)= -4
 =n^2-2n+2n-4
 = n^2-4
        
             
        
        
        
Answer:
the first one
Step-by-step explanation:
 
        
                    
             
        
        
        
First we need to find the length. So we do 126/3 to get 42. The length is 42. Now to find perimeter we do 2(42)+2(3) or 42+42+3+3.
Both ways are right ways. The perimeter is 90 meters.
Hope that helps!!
 
        
             
        
        
        
A trapezoid is a rectangle.