The answer is 52,000. 
You have to add all of the values and divide them by the number of values. In this case you would do 30,000 + 50,000 + 30,000 + 80,000 + 70,000 which equals 260,000 then you would divide that number by 5 since there are 5 values. 
 
        
             
        
        
        
Step-by-step explanation:
-(-5x + 3) = 17
5x - 3 = 17
5x = 20
x = 4.
 
        
             
        
        
        
27.5 and 22.5 are the two numbers
        
             
        
        
        
Answer:
y = 29
Step-by-step explanation:
y = (3x)2 + 17
y = (3(2))2 + 17
y = (6)2 + 17
y = 12 + 17
y = 29
 
        
             
        
        
        
600/12 = 50 student are girls
Mark brainliest please 
Hope this helps you