The method of completing the square was used to solve the equation 2x^2 - 12x + 6 =0 which equation is a correct step when using this method ? 1- (x - 3 )^2 =6 2- (x - 3 )^2 =-6 3- (x - 3 )^2 =3 4- (x - 3 )^2 = -3

The equation we are looking at would have to be divided by 2 first.
x²-6x+3
When looking at that, I can tell that 1 may be the possible answer since you would have to subtract 6 from both sides. That would leave a 3. Let's check.
(x-3)(x-3)
x²-6x+9=6
Now subtract 6 from both sides.
x²-6x+3=0
So, 1- (x-3)²=6 would be used.