Answer: is it -3,11
Step-by-step explanation:
 
        
             
        
        
        

Rounding to nearest thousand gives 76,000 mg of chlorine
 
        
             
        
        
        
5 is a coefficient.  A coefficient is a number multiplied by a variable.
(2y+13) is a factor.  It can be multiplied by 8 to get an extended answer.
-1 is a constant.  A constant is a number that does not change.
Hope this helps!