Answer:
the answer is 19
Step-by-step explanation:
 
        
                    
             
        
        
        
No, 

 is not a subspace of 

. A simple counter-example to the contrary: let 

 with 

. However, scaling by -1 gives the vector 

 and 

.
 
        
        
        
Answer:
It is 20
Step-by-step explanation:
Use your fingers if necessary
 
        
             
        
        
        
Answer:
8
Step-by-step explanation:
There are 2 cheeses, american and cheddar, and 4 meats, ham, bologna, turkey, and chicken. For every cheese, there are 4 options of meat. So then there are 2*4=8 sandwiches. If you are familliar with this concept, just multiply 2 and 4.