x^2 - 12x + 36 = 0?

x^2 - 12x + 36 = 0
(x-6)(x-6) = 0
x = 6

x = [ 12 ± √ (144 - 144 ) ] / 2
x = 6 (twice)
OR
(x - 6)(x - 6) = 0
x = 6 (twice)

i've got faith you mean x^2 (x squared) for the 1st area. if so it would be factored to (x+6)^2. You get this because of the fact which you're taking the sq. root of 36 and get 6. Then something continues to be the comparable.

x^2 - 12x + 36 = 0
(x - 6)(x - 6) = 0
x = 6

x^2 - 12x + 36 = 0
(x - 6)(x - 6) = 0

x - 6 = 0
x = 6

∴ x = 6

x² - 12x + 36 = 0
The discriminant is: D=12² - 4*36 = 144 - 144 = 0
x = 12/2 = 6

--------
ax² + bx + c = 0
D = b² - 4ac
x = (- b ± √D)/2a

For quadratic equations like Ax^2 + Bx + C = 0, use the following formula:

x = [ -B +(-) sqrt(B^2 - 4AC) ] / 2A

Two solutions, according to using + or (-) in that equation

Then, identifying the elements:
A = 1
B = -12
C = 36

Finally, the two solutions are the same: x = 6