This is a 4x4 magic square of multiplication,
in which product of each row, column, and diagonal are equal.
$\begin{bmatrix}2 & 15 & 50 & 18\\ 9& 30& 4& 25\\ 20& 5& 45& 6\\ 75& 12& 3& 10\end{bmatrix}$
Now modify the magic square by defining a simple algorithm $f(x)$,
so it becomes a new magic square of addition,
in which sum of each row, column, and diagonal are equal.
$\begin{bmatrix}f(2) & f(15) & f(50) & f(18)\\ f(9) & f(30)& f(4)& f(25)\\ f(20)& f(5)& f(45)& f(6)\\ f(75)& f(12)& f(3)& f(10)\end{bmatrix}$
Note:
- The algorithm works to every magic square of multiplication.
- The numbers in the new magic square must be integers
- some numbers in the new magic square can be equal, but not all
- Avoid using $f(x) = C$