If the vertex of the parabola is (h,k) the equation of the parabola will be
y = a(x - h)² + k
From the question (h,k) is (2,-4) then the equation of the parabola will be
y = a(x - 2)² + (-4)
Compare the equation
y = a(x - 2)² + (-4)
with
y = 9(x - 2)² + v
The value of a is 9 and the value of v is (-4).
The answer of the question ⇒ the value of v is (-4)