Check how much each number differs from the previous one. Is there any pattern?
This is similar to your 7:58pm post. In that case we interpreted x^2y as x^(2y) rather than (x^2)y. In that case y was 1, and the value was the same. In this case, I don't see any answers if x is raised to the 2y power. If it is interpreted as 5(x^2)y for the numerator and...
putting a few parenthesis in for clarification... 2x^(2y)/(4xy) does = 1 for x=2 and y=1 So, you are correct!
I think that the 4 is probably inside the "crook" of the radical sign to indicate the fourth root of (81/16).
I got a, also.
If the problem is asking for the fourth root of 625, then c is correct. That would be the case if the 4 is in the crook of the radical sign.
a is NOT correct.
Glad to help.
Yes, I got b, also.