Why matrices with different dimensions cannot be added

Adding two 2x2 matrices by matching corresponding entries

Why matrices with different dimensions cannot be added

Adding two 3x3 matrices by matching corresponding entries

Adding two 2x2 matrices with negative entries

Adding three 3x3 matrices to get a zero matrix

Subtracting two 2x2 matrices with negative entries

Subtracting two 3 by 3 matrices with negative entries

Subtracting three 2x2 matrices by corresponding entries

Solving for an unknown matrix A using isolation

Solving a matrix equation by isolating the unknown matrix

Solving for six unknown variables in a matrix equation