Answer:
k = 3
Step-by-step explanation:
Given
x² + y² + 6y - 4 = 0 ( add 4 to both sides )
x² + y² + 6y = 4
Using the method of completing the square
add ( half the coefficient of the y- term )² to both sides
x² + y² + 2(3)y + 9 = 4 + 9
x² + (y + 3)² = 13
with k = 3