What value should be added in the blanks to complete the square?

The answer to your question is letter C. 16

Step-by-step explanation:

Data

Polynomial           x² + 8x +

To complete the square,

1.- Just divide the coefficient of middle term by two

Middle term = 8x

                       8/2 = 4

2.- Write 4² in both sides of the equations.

      x² + 8x + 4² + y² + 10y + 25 =  - 15 + 4²          

3.-   Expand 4²

                    4² = 16      

{3 + i, 3 - i, 3, -1}

step-by-step explanation: