What is the positive solution to the eqution 0=1/3x^2-3

It's 3 ...

First you add 3 to both sides. (1/3x^2=3)

Then multiply both sides by 3. (x^2=9)

Then take the square root of both sides. (x=+-3)

Finally since it is asking for the positive solution, you can remove the negative sign and so the answer is 3.