Let $A$ is a given matrix, then $(-A)$ is a skew-symmetric matrix. Similarly, for a given matrix $-B$ is a skew-symmetric matrix. Hence, $-A-B=-(A+B) \Rightarrow$ sum of two skew-symmetric matrices is always skew-symmetric matrix.

Let $A$ is a given matrix.

$\therefore \quad-A=-1[A]$

So, the negative of a matrix is obtained by multiplying it by $-1$.

The product of any matrix by the scalar 0 is the null matrix. i.e., $0 \cdot A=0$. [where, $A$ is any matrix]

A matrix which is not a square matrix is called a rectangular matrix. For example a rectangular matrix is $A=\left[a_{i j}\right]_{m \times n}$, where $m \neq n$.

Matrix multiplication is distributive over addition.

e.g., For three matrices $A, B$ and $C$,

(i) $A(B+C)=A B+A C$

(ii) $(A+B) C=A C+B C$