Question

Find matrix $X$, if $X+\left[\begin{array}{cc}4& 6\\ -3& 7\end{array}\right]=\left[\begin{array}{cc}3& -6\\ 5& -8\end{array}\right]$.

Answer 1

$\begin{array}{c}X+\left[\begin{array}{cc}4& 6\\ -3& 7\end{array}\right]=\left[\begin{array}{cc}3& -6\\ 5& -8\end{array}\right]\\ X=\left[\begin{array}{cc}3& -6\\ 5& -8\end{array}\right]-\left[\begin{array}{cc}4& 6\\ -3& 7\end{array}\right]\\ X=\left[\begin{array}{cc}3-4& -6-6\\ 5+3& -8-7\end{array}\right]\\ hence,\\ X=\left[\begin{array}{cc}-1& -12\\ 8& -15\end{array}\right]\end{array}$