Answer:
75
Step-by-step explanation:
Four scores....  add them together and divide by four 
  (90 + 80 + 70 + 60) / 4 = 75
 
        
             
        
        
        
Answer:
12 is missing
Step-by-step explanation:
 
        
             
        
        
        
Answer:
30%
Step-by-step explanation:
the first solution -30% will be 45% and the second solution added by 30% will be 45%
 
        
                    
             
        
        
        
Step-by-step explanation:
inner region
A=πr^2
A=π*6^2
A=π*36cm^2
A=113.09cm^2
shaded region(outer)
A=πr^2
A=π*9^2
A=π*81cm^2
A=254.46cm^2
Area of shaded region=254.46cm^2-113.09cm^2
 =141.37cm^2
Mark brianliest if my answer suit your question 
 
        
                    
             
        
        
        
I got x=-4 for the answer