Answer:
2.236
Step-by-step explanation:
you could estimate it to be between 2 and 3 (because 5 is between 4 and 9)
or you just put it into a calculator
 
        
             
        
        
        
Answer:
320km/h
Step-by-step explanation:
You simply times 80 km by 4hr to get 320 km/h
 
        
                    
             
        
        
        
I know the B is 2
Sorry I don't know the A
        
             
        
        
        
Just replace x with whatever , and see if it works. If it works then it is a solution; otherwise it's not. 
1^2 is not 2
(1/2)^2 isn't 2 either...
and so on