Respuesta :

Answer:

6

Step-by-step explanation:

y varies directly with x means:

y = kx

Given that y = 3 when x = 9:

3 = 9k

k = 1/3

Therefore:

y = 1/3 x

When x = 18:

y = 1/3 (18)

y = 6

Answer: 6

hope it's right