Your answer is 9 to the 3 power, where the blank is 3.
To find this, I first wrote out the equation:

Then I found the value of (1/9)^-3, which you can do by first flipping the fraction 1/9 as the power is negative, to get 9/1, or just 9, and then putting 9 to the power of 3 to get 27.
You could have already noticed that we got 9³ = 9^x, so x = 3, but if you didn't then you would just need to see that 27 is 9³.
I hope this helps!