Find a matrix `A` , if `A+[2 3-1 4]=[3-6-3 8]` .

Explanation

Given : $$A+\left[\begin{array}{cc}2 & 3 \\ -1 & 4\end{array}\right]=\left[\begin{array}{cc}3 & -6 \\ -3 & 8\end{array}\right]$$
$$\Rightarrow A=\left[\begin{array}{cc}3 & -6 \\ -3 & 8\end{array}\right]-\left[\begin{array}{cc}2 & 3 \\ -1 & 4\end{array}\right]$$
$$\Rightarrow A=\left[\begin{array}{cc}3-2 & -6-3 \\ -3+1 & 8-4\end{array}\right]$$
$$\Rightarrow A=\left[\begin{array}{cc}1 & -9 \\ -2 & 4\end{array}\right]$$