Question 908884
{{{x^2-12x+4=0}}}, not factorable.


Study how to complete the square:  <a href="http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev">http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev</a>


Add {{{(-12/2)^2=36}}}  to both sides and identify and factor the appropriate trinomial; and then solve for x.


OR, if you already know the general solution for a quadratic equation, use that.


(Note that discriminant will be 128, which is {{{(-12)^2-4*4}}}).
(Note that {{{128=2^7}}}  ).