Answer:
100 
Step-by-step explanation:
i got it right on the test !! 
 
        
             
        
        
        
When we say "closed under addition" in the context of rational numbers, we mean to say that when we add up rational numbers then, the sum is also a rational number. 
From the given choices above, the one that should the characteristic of being "closed under addition" is only fourth equation. Both 1/2 and 0.5 are rational numbers. On the other hand, 1 is also a rational number. 
        
             
        
        
        
Let n be the unknown value
n + (n+2) + (n+4) = 408
Then we would simplify by combining like terms
n + n + 2 + n + 4 = 408
3n+6=408
     -6     -6
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3n=402
Divide. 
3n=402
--    ----
3      3
n = 134. 
So the first integer is 134. Then plug in the rest to the n+2 and n+4
134+2= 136
134+4= 138
The integers are then 134, 136, 138
        
             
        
        
        
A. If the weight of the bag exceeds 50 pounds, then you will have to pay a fee. If W>50, then you will pay a fee.
B. Any number below 51 (not including 51) will make this inequality false.