What is thevalue of x k 30 j45 8÷2

First row
∴ x = -9
∴ (1/3)x + y = 12
   (1/3)(-9) + y = 12
   -3 + y = 12
∴  y = 15

Second row
∴ x = -3
∴(1/3)x + y = 12
  (1/3)(-3) + y = 12
  -1 + y = 12
∴ y = 13

Third row
∴ x = 0
∴(1/3)x + y = 12
  (1/3)(0) + y = 12
  0 + y = 12
∴ y = 12

Fourth row
∴ x = 3
∴(1/3)x + y = 12
  (1/3)(3) + y = 12
  1 + y = 12
∴ y = 11

Fifth row
∴ x = 9
∴(1/3)x + y = 12
  (1/3)(9) + y = 12
  3 + y = 12
∴ y = 9