The answer is ±3
First, you should make one side of the quadratic 0. You can do this by subtracting 17 from both sides, making the equation
2/3x^2 - 18 = 0
To make everything an integer, you can multiply both sides by 3/2, making the equation
x^2 - 27 = 0
By adding 27 to both sides, you get
x^2 = 27
Now you are practically done! By taking the square root of both sides, you get
x = ±3