The answer is 24x^2 + 80x + 24
        
             
        
        
        
The answer is 2,320 seats in the amphitheater. Since the seats are increasing at a rate of 4 more seats each row, then just add 4 to the number for each past row starting at 32 since that's where the rest is unknown. Once you find all he numbers just add them up to get your answer. 
I hope I helped!
        
             
        
        
        
Answer:
24/10 or 2 and 4/10 
Step-by-step explanation: 
 
        
             
        
        
        
Answer:
11.78
Step-by-step:
78x + 8x + 12x + 20x + 28x
78x + 32x + 28x
= 138x
1626.35/138
= 11.78
 
        
             
        
        
        
I think the answer is 2 because 1.5=1 1/2 so 1+1/2+1/2=2