Question

If $A=\left[\begin{array}{ccc}1& -2& 4\\ 2& 3& 2\\ 3& 1& 5\end{array}\right]$ and $B=\left[\begin{array}{ccc}0& -2& 4\\ 1& 3& 2\\ -1& 1& 5\end{array}\right]$, then $A+B$ is

• A. $\left[\begin{array}{ccc}1& -2& 4\\ 3& 3& 2\\ 2& 1& 5\end{array}\right]$
• B. $\left[\begin{array}{ccc}1& -2& 8\\ 3& 3& 4\\ 2& 1& 10\end{array}\right]$
• C. $\left[\begin{array}{ccc}1& -4& 8\\ 3& 6& 4\\ 2& 2& 10\end{array}\right]$
• D. none of these

Answer 1

The correct option is C $\left[\begin{array}{ccc}1& -4& 8\\ 3& 6& 4\\ 2& 2& 10\end{array}\right]$

Given, $A=\left[\begin{array}{ccc}1& -2& 4\\ 2& 3& 2\\ 3& 1& 5\end{array}\right]$ and $B=\left[\begin{array}{ccc}0& -2& 4\\ 1& 3& 2\\ -1& 1& 5\end{array}\right]$
Therefore, $A+B=\left[\begin{array}{ccc}1+0& -2-2& 4+4\\ 2+1& 3+3& 2+2\\ 3-1& 1+1& 5+5\end{array}\right]$

$=\left[\begin{array}{ccc}1& -4& 8\\ 3& 6& 4\\ 2& 2& 10\end{array}\right]$