Subtraction of Matrices

Q.

Evaluate $3\left[\begin{array}{cc}1& -1\\ -2& 0\\ 1& -2\end{array}\right]-\left[\begin{array}{cc}-5& 2\\ -1& 3\\ 4& -4\end{array}\right]$

1. $\left[\begin{array}{cc}8& -5\\ 7& 4\\ 1& 2\end{array}\right]$

2. $\left[\begin{array}{cc}2& 1\\ 5& 3\\ -1& -2\end{array}\right]$

3. $\left[\begin{array}{cc}8& 5\\ 5& 3\\ 1& 2\end{array}\right]$

4. $\left[\begin{array}{cc}8& -5\\ -5& -3\\ -1& -2\end{array}\right]$

Q.

If $\left[\begin{array}{cc}5& 4\\ 8& -3\end{array}\right]-3X=\left[\begin{array}{cc}-4& 7\\ 5& -9\end{array}\right]$.

Find X?

1. $\left[\begin{array}{cc}3& 1\\ 1& 2\end{array}\right]$

2. $\left[\begin{array}{cc}3& -1\\ 1& 2\end{array}\right]$

3. $\left[\begin{array}{cc}-3& -1\\ 1& 2\end{array}\right]$

4. $\left[\begin{array}{cc}3& -1\\ -1& 2\end{array}\right]$

Q. If $A=\left[\begin{array}{cc}4& 2\\ -1& 1\end{array}\right]$ and I is the identity matrix of order 2, then (A - 2I)(A - 3I) =

1. $I$
2. $0$
3. $\left[\begin{array}{cc}1& 0\\ 0& 0\end{array}\right]$
4. $\left[\begin{array}{cc}0& 0\\ 0& 1\end{array}\right]$