The inverse matrix of $2 \times 2$ matrix is $\mathrm{A}^{-1}=\frac{1}{\mathrm{ad}-\mathrm{bc}}\left[\begin{array}{cc}d & -b \\-c & a\end{array}\right]$.
The inverse of $3 \times 3$ Matrix can be caluculated by the formula $A^{-1}=\frac{1}{|A|} \cdot \operatorname{adj}(A)$
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile