Question:
If $A$ and $B$ are square matrices of the same order, then $(A+B)(A-B)$ is equal to
(a) $A^{2}-B^{2}$
(b) $A^{2}-B A-A B-B^{2}$
(c) $A^{2}-B^{2}+B A-A B$
(d) $A^{2}-B A+B^{2}+A B$
Solution:
$(A+B)(A-B)=A^{2}-A B+B A-B^{2}$
Hence, the correct option is (c).