Find matrices $A$ and $B$, if $2 A-B=\left[\begin{array}{rrr}6 & -6 & 0 \\ -4 & 2 & 1\end{array}\right]$ and $2 B+A=\left[\begin{array}{ccc}3 & 2 & 5 \\ -2 & 1 & -7\end{array}\right]$
Add 2(2A-B) and (2B+A)
$2(2 A-B)+(2 B+A)=2\left(\left[\begin{array}{ccc}6 & -6 & 0 \\ -4 & 2 & 1\end{array}\right]\right)+\left[\begin{array}{ccc}3 & 2 & 5 \\ -2 & 1 & -7\end{array}\right]$
$5 A=\left(\left[\begin{array}{ccc}12 & -12 & 0 \\ -8 & 4 & 2\end{array}\right]\right)+\left[\begin{array}{ccc}3 & 2 & 5 \\ -2 & 1 & -7\end{array}\right]$
$5 A=\left[\begin{array}{ccc}15 & -10 & 5 \\ -10 & 5 & -5\end{array}\right]$
$A=\left[\begin{array}{ccc}3 & -2 & 1 \\ -2 & 1 & -1\end{array}\right]$
$B=2\left(\left[\begin{array}{ccc}3 & -2 & 1 \\ -2 & 1 & -1\end{array}\right]\right)-\left[\begin{array}{ccc}6 & -6 & 0 \\ -4 & 2 & 1\end{array}\right]$
$=\left[\begin{array}{ccc}6 & -4 & 2 \\ -4 & 2 & -2\end{array}\right]-\left[\begin{array}{ccc}6 & -6 & 0 \\ -4 & 2 & 1\end{array}\right]$
$B=\left[\begin{array}{ccc}0 & 2 & 2 \\ 0 & 0 & -3\end{array}\right]$
Conclusion: $\mathrm{A}=\left[\begin{array}{ccc}3 & -2 & 1 \\ -2 & 1 & -1\end{array}\right], \mathrm{B}=\left[\begin{array}{ccc}0 & 2 & 2 \\ 0 & 0 & -3\end{array}\right]$
(GIVEN ANSWER IS WRONG for question 8)