Respuesta :

Answer: 4

Step-by-step explanation:

  3x - 12y - 9  =   9x + (x + 4y - 3)

3x + 12y = 9

x + __ y = 3

Divide the first equation by 3 to get the second equation:

3x /3 = x

9/3 = 3

12y /3 = 4y

The answer would be D. 4