Given $P = P'$ and $Q=Q'$ $\left(PQ-QP\right)'=\left(PQ\right)'-\left(QP\right)^{'}$ $=\left(Q'P'- P'Q'\right)=QP-PQ$ $-\left[PQ-QP\right]$ $\therefore\, \left(PQ-QP\right)$ is skew symmetric.
A matrix is a rectangular array of numbers, variables, symbols, or expressions that are defined for the operations like subtraction, addition, and multiplications. The size of a matrix is determined by the number of rows and columns in the matrix.
The basic operations that can be performed on matrices are:
Addition of Matrices - The addition of matrices addition can only be possible if the number of rows and columns of both the matrices are the same.
Subtraction of Matrices - Matrices subtraction is also possible only if the number of rows and columns of both the matrices are the same.
Scalar Multiplication - The product of a matrix A with any number 'c' is obtained by multiplying every entry of the matrix A by c, is called scalar multiplication.
Multiplication of Matrices - Matrices multiplication is defined only if the number of columns in the first matrix and rows in the second matrix are equal.
Transpose of Matrices - Interchanging of rows and columns is known as the transpose of matrices.