Verified answer

Answer:

285

Step-by-step explanation:

12+7{31 - [4 (2-1-3)]}​

12+7{31 - [4 (-2)]}​

12+7{31 - [-8]}​

12+7{31 + 8}​

12+7{39}​

12 + 273

285

Answer:

285.............................