what's the question? you only put a formula
 
        
             
        
        
        
Answer:
100m 
Step-by-step explanation:
just subtract them from each other
                                  
                                            500m
                                        -   400m
                                          -----------
                                            100m
 
        
                    
             
        
        
        
Answer:
7200 mg 
Step-by-step explanation:
multiply the mass value by 1000
 
        
                    
             
        
        
        
Answer:
Store A: 4
Store B:  1
Store C: 3
Store D: 2
Step-by-step explanation:
I got it right