2 1 4 --- - --- - --- 3 6 9 ------------------- 7 5 5 --- - --- - --- 9 12 18

Question

2 1 4
--- - --- - ---
3 6 9
-------------------
7 5 5
--- - --- - ---
9 12 18

Answer 1

2/3-1/6-4/9=12/18-3/18-8/18=1/18

7/9-5/12-5/18=28/36-15/36-10/36=3/36=1/12