Question

The matix $\left|\begin{array}{cc}1& -4\\ 1& -5\end{array}\right|$ is an inverse of the matix

• A. Ture
• B. False

Answer 1

The correct option is A Ture

$A{A}^{-1}=1$
$\left[\begin{array}{cc}5& -4\\ 1& -1\end{array}\right]\left[\begin{array}{cc}1& -4\\ 1& -5\end{array}\right]=\left[\begin{array}{cc}5-4& -20+20\\ 1-1& -4+5\end{array}\right]=\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right]$
So, the given statement is true