Answer:
-9
Step-by-step explanation:
Since h(x) = x^2 + 3 and g(x) = x^2 -6, they only differ by about 9 units or 3 --6 = 9. This means a value was added /subtracted to h(x) to get g(x). This value is k.
So g(x) = h(x) - 9 where k = -9, since x^2 + 3 - 9 = x^2 -6.