Answer:
14
Step-by-step explanation:
 
        
                    
             
        
        
        
S=((294+3)*(294/3))/2=14553
        
             
        
        
        
I think x=24 but not sure
        
                    
             
        
        
        
Answer:
132 people bought balcony tickets and 450 bout ground tickets
Step-by-step explanation:
let x be balcony and y for ground
x+y=582
15x+10y=6480  solve by adding(subtracting)/eliminating process
multiply first equation by 15 to eliminate x:
15x+15y=8730
15x+10y=6480      subtract
15x+15y-15x-10y=8730-6480
5y=2250
y=2250/5=450 
x+y=582
x=582-450=132