How would you solve by completing the square?

3x^2 + X - 1/2= 0

3x^2 + X = 1/2

x^2 + x/3 = 1/6
x^2 + x/3 + 1/36 = 1/6 + 1/36
(x+1/6)^2 = 7/36
x+1/6 = ± √7 / 6
x = -1/6 ± √7 /6 = (-1 ± √7)/6