Answer:
1/9
You are being asked to "complete the square"
you need to find a value to make the quadratic a "perfect square:
the focus is -2/3 you need to "add" one half of -2/3 squared to the
equation (1/2 * -2/3)^2 .... (-2/6)^2 .... 4/36 .... 1/9
Explanation: