Answer:
the answer is C 
Step-by-step explanation:
because the negative needs to be on the inside not on the outside
 
        
                    
             
        
        
        
Aidan has put 21 hours of work. To simplify it, Harry worked 7 hours and Aidan worked 7 x 3 times which equates to 21 hours.
        
                    
             
        
        
        
Eliminate the fractions by multiplying by least common multiple.
4,9,12 all go into 36 evenly. Multiply entire equation by 36.
36/4 = 9
36/9 = 4
36/12 = 3
New equation looks like:
 
 
        
        
        
Answer:
-11 and lower
Step-by-step explanation:
it's saying that -10 is as low as the number can possibly be or equal to it.