How to calculate this math problem, (horizontal, vertical, diagonal sum can be equal), in short, in the fourth grade of primary school, don't use X and Y.
There is a rule in this kind of problems that the middle number must be the average of all numbers, so the sum is 5.5*3 = 17.5.
Then you can get the answer 5.4 5.9 5.2.
5.3 5.5 5.7
5.8 5. 1 5.6