Math

3x^2+x-2=0

3x ² + x = 2

3(x ² +(1/3)x) = 2

x ² + (1/3)x = (2/3)

now [(1/3) divided by 2] squared = 1/36: add this to both sides

x ² + (1/3)x + (1/36) = 2/3 + 1/36

(x + 1/6) ² = 25/36

x + 1/6 = +5/6 OR x + 1/6 = -5/6

and you can finish it.