Transform the required form of the expression -2 * (x - p) ^ 2 + q = 0 opening parenthesis:
-2 (x^2 - 2px + p^2) + q
-2x^2 + 4px - 2p^2 + q
It has to be the same for all values of X with the original expression - 2x ^ 2 - 12x = 12 :
-2x^2 - 12x - 12
It happens when all corresponding coefficients are equal:
-2 = -2
+4p = -12
-2p^2 + q = -12
Solving this system of equations:
p = -3
q = 6
It is called "method of undetermined coefficients"

LEV K.
12/14/19