Hello from MrBillDoesMath!
Answer: C)
Discussion:
To solve x^2 = 36/81 take the square root of both sides.
x = square root of (36/81)
As 36 = 6*6 and 81 = 9*9,
x = square root of (6*6)/ (9.9) or 6/9
But 6 and 9 share the common factor "3" so
x = 6/9 = (2*3)/(3*3) = 2/3
The last equality was gotten by cancelling the common factor 3.
Regards, MrB
