for all positive integers (like n = 1, 2 or 5) the conjecture holds true but not for negative values like if n = -3 then the result will not become positive, because:

which is not positive.
I think that it would be B). 1/2
The reason I think that is because if you add all the marbles up you get 22. Then if you add the red and the green marbles you get 11. 11 is half of 22 making it a 50% chance. 1/2 is the same as 50% or a half.
Okay so combine like terms
10x-4x= 6x
2-8= -6
6x=-6
x= -1
Now to check:
10(-1)-2=4(-1)-8
-10-2=-4-8
-12=-12
The missing number is 12
because the pattern is that the the numbers below and to the right of a number equals that number. ex: 3+4=7. so in order to find the missing number you have to do the opposite of addition, which is subtraction. (17-5=12)
Option C, 36, because it is the LCM (Least common multiple)