X+y and y+x are the same as stated by the commutative law.
This is because let’s say x=2 and y=3,
2+3=5 and 3+2=5
        
             
        
        
        
53/100 ÷ 5 can be reduced down to 
  7
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 20 
Good Luck! :)
        
             
        
        
        
Here u go the answer is 4/3
        
             
        
        
        
8,9,10
how i found this out was if u replace m with 8 it will be 8+7 which is 15 and less then 18
for 9 its 9+7 which is 16 which is less then 18
and for 10 its 10+7 which is 17 which is less then 18
and for 11 its 11+7 is 18 which is equal to 18 so it would not apply to this equation
hope this helps