X=9 is the answer for this
        
             
        
        
        
9 is 22.5% of 40 if that's the question.
        
                    
             
        
        
        
Answer:

Step-by-step explanation:
Given

Required
Simplify the expression

Express the square root of 121 as 11


Express 90 as 9 * 10

Split the surd to 2

Express the square root of 9 as 3



Hence, the result of the expression is 

 
        
             
        
        
        
9514 1404 393
Answer:
   6/20, 3:5, 50/100 are all less than 8/10
Step-by-step explanation:
It can help to give all the ratios a common denominator. (We'll use 100, and fudge the last one a bit.)
   8/10 = 80/100 . . . . our reference value
__
   6/20 = 30/100 . . . less than 8/10
   3/5 = 60/100 . . . . less than 8/10
   50/100 . . . . . . . . . less than 8/10
   13/15 ≈ 86.7/100 . . . more than 8/10