Find x, where x^6 = 9^-3 and x > 0

X^6 = (3^2)^-3
Translated this becomes

x^6 = 3^-6
x^6 = 1/3^6 Now you take the 1/6th root of both sides.
x = +/- 1/3 <<<<
I'm seeing if the equation editor does what it says it will do. You have the information to get the answer.