Addition and subtraction of a matrix

Q. $\mathrm{Let}A+2B=\left(\begin{array}{ccc}1& 2& 0\\ 6& -3& 3\\ -5& 3& 1\end{array}\right]\mathrm{and}2A-B=\left(\begin{array}{ccc}2& -1& 5\\ 2& -1& 6\\ 0& 1& 2\end{array}\right],\mathrm{then}\mathrm{find}\mathrm{tr}\left(A\right)-\mathrm{tr}\left(B\right).$

1. 3
2. -1
3. 2
4. -3

Q.

If A = $\left[\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\\ 7& 8& 9\end{array}\right]$ and B = $\left[\begin{array}{ccc}4& 5& 6\\ 7& 8& 9\\ 1& 2& 3\end{array}\right]$ then the order of A+B will be nxn where n= -----

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