Answer:
B. 36
Explanation:
The equation in question is not well written. Let the equation be;
x²+12x+5 = 0
In order to know what number should be added to both sides of the equation, we will take the square of the half of coefficient of x as shown;
Coefficient of x = 12
Half of 12 = 1/2(12) = 6
Square of 6 = 6² = 36
Hence the required number to add to both sides of the equation by completing the square method is 36