Respuesta :

Answer:

k = 1

Step-by-step explanation:

=> y ∝ x²

So, y = kx²    ----------------------------(1)

Where k is the constant of proportionality

Now,

y = 9 when x = 3

Putting in (1)

=> 9 = k(3)²

=> 9 = k(9)

Dividing both sides by 9

=> k = 1