Question

Solve the following matrix equation for $x:\left[x1\right]\left[\begin{array}{cc}1& 0\\ -2& 0\end{array}\right]=0.$

Answer 1

Given , $\left[\begin{array}{cc}x& 1\end{array}\right]\left[\begin{array}{cc}1& 0\\ -2& 0\end{array}\right]=0$
$\left[\begin{array}{cc}x& 1\end{array}\right]\left[\begin{array}{cc}1& 0\\ -2& 0\end{array}\right]=\left[\begin{array}{cc}x-2& 0\end{array}\right]=0$
which implies $x-2=0$ , which gives $x=2$