**Question:**

Matrix multiplication is over matrix addition.

**Solution:**

Matrix multiplication is distributive over matrix addition.

Let $A, B$ and $C$ be three matrices. Then

(i) $A(B+C)=A B+A C$, whenever both sides of equality are defined

(ii) $(A+B) C=A C+B C$, whenever both sides of equality are defined

Matrix multiplication is **distributive** over matrix addition.