Take various square matrices A; compute the transpose of A and call it B. Then calculate A + B and A - B.
What sort of matrix is A + B ?
What sort of matrix is A - B ?
Can you prove your conjectures?
Verify the identity A = (A + B)/2 + (A - B)/2.
What can you say about expressing an arbitrary square matrix in terms of matrices of special types? Can you prove (or have you already proved) your answer?