回複：Yes. Do you have a fast and easy way to explain it?

write the magic square as

a x y
z w 47
b 63 c

Then we have
S = a+x+y
= x+w+63
= y+47+c
= a+w+c
= ...
Now adding the 1st and the 4th and subtracting the 2nd and 3rd gives 2a-63-47=0, which solves to a=55.