Answer:
A&C
Step-by-step explanation:
(x + 3)² = 15
Given
x² + 6x - 6 = 0 ( add 6 to both sides )
x² + 6x = 6
To complete the square
add (half the coefficient of the x- term )² to both sides
x² + 2(3)x + 9 = 6 + 9
2 is D and 12 is C
3