Multiplication matrix A by matrix B can be applied if and only if the number of columns of matrix A equal to the number of rows of matrix B. The result matrix dimensions: number of rows equal to the number of rows of matrix A and number of columns equal to the number of columns of matrix B:
An × m ∙ Bm × k = Cn × k
Matrices multiplication is noncommutative operation:
A ∙ B ≠ B ∙ A
| A | = |
| B | = |