Formula of doing unknown matrix ?

There is no specific formula for finding an unknown matrix as it depends on the specific problem or context in which the matrix is being used. However, some common methods for finding unknown matrices include solving systems of linear equations, using matrix operations such as addition, subtraction, multiplication, and inversion, and using techniques such as Gaussian elimination or matrix decomposition. It is important to carefully analyze the given information and constraints in order to determine the appropriate approach for finding the unknown matrix.

[A] = [B] x [C]

where:

- [A] is the unknown matrix
- [B] is a known matrix
- [C] is a known matrix