Answer
$A^{-1}=\left[\begin{array}{ll}
-1 & -1/2\\
-3 & -2
\end{array}\right]$
Work Step by Step
Technology used: the free online calculator at
www.geogebra.org/classic/cas
The syntax for defining a matrix:
A:= { { row 1}, {row 2} ... { row n} },
(the elements in rows are delimited with commas)
(A "colon equals" assigns the matrix to A).
The command for $B=A^{-1}$ is B:= Invert ( A ).
(B "colon equals" assigns the matrix to B).
Check by multiplying the matrices
AB=BA=I
Please see screenshot below.
$A^{-1}=\left[\begin{array}{ll}
-1 & -1/2\\
-3 & -2
\end{array}\right]$
