Question:
If $A$ and $B$ are square matrices of the same order then $(A+B)(A-B)=?$
A. $\left(A^{2}-B^{2}\right)$
B. $A^{2}+A B-B A-B^{2}$
C. $A^{2}-A B+B A-B^{2}$
D. none of these
Solution:
Since $\mathrm{A}$ and $\mathrm{B}$ are square matrices of same order.
$(A+B)(A-B)=A^{2}-A B+B A-B$