Matrix Addition and Subtraction

Find A + B, where A = $\left(\begin{array}{cc}1& 2\\ 3& 4\end{array}\right)$ and B = $\left(\begin{array}{cc}5& 6\\ 7& 8\end{array}\right)$.

• 1Add matching elements: top-left: $1+5=6$, top-right: $2+6=8$
• 2Bottom-left: $3+7=10$, bottom-right: $4+8=12$

Answer: $\left(\begin{array}{cc}6& 8\\ 10& 12\end{array}\right)$

Find A − B, where A = $\left(\begin{array}{cc}5& 2\\ 0& -3\end{array}\right)$ and B = $\left(\begin{array}{cc}1& 4\\ 2& -1\end{array}\right)$.

• 1Subtract matching elements: top-left: $5-1=4$, top-right: $2-4=-2$
• 2Bottom-left: $0-2=-2$, bottom-right: $-3-(-1)=-2$

Answer: $\left(\begin{array}{cc}4& -2\\ -2& -2\end{array}\right)$