Properties of matrix addition

Verifying the matrix addition properties
You are given that and and . Verify the following properties:
1. Commutative property $(A+B=B+A)$
2. Associative property $(A+B)+C=A+(B+C)$
3. Dimension property for addition
You are given that and and . Verify the following properties:
1. Commutative property $(A+B=B+A)$
2. Associative property $(A+B)+C=A+(B+C)$
3. Dimension property for addition
Let . Verify the zero matrix property.
Let $X$ be a 2 x 2 matrix. Show that $I_n \cdot X=X$ .