Answer:
The answer for this question would be maybe D-  
SORRY IF I'M WRONG
 
        
             
        
        
        
Sometimes it will, and sometimes it won't.
I reason as follows:
(21 + x)  +  (30 + 2x)  =  51 + 3x      has an 'x' term
(42 + x)  +  (30 - x)  =  72                  has no 'x' term.
        
             
        
        
        
The answer is 221,448,757.5 
Remember to use PEMDAS
        
                    
             
        
        
        
I can simplify the formula with the data you gave me to do a simple formula like this: <span>4.25 k + 2 p = 12 I think this one explains in an easy way this. Hope it's good for you</span>