The answer is C., and you figure this out through completing the square
First bring 2 to the other side of the equation making it x^2 -6x =2
Then find a new c term by doing (b/2)^2
This is (-6/2)^2 which is (-3)^2, = 9
Now you have x^2 -6x + 9 =-2. However since you added 9 to one side of the equation, you must add 9 to the other side in order to balance it out
So it is x^2 -6x+9 = -2+9
Factor the first side of the equation and add the second side to simplify:
(x-3)^2 = 7
Take the square root of both sides and you get x-3 is equal to the square root of plus/minus 7
Then add three to both sides to isolate x and you get your final result which is x= 3 plus/minus radical 7
