TeX джерело:

A^{-1}\;=\;-\,\frac{1}{15}\;\left(\begin{array}{rrr}-2&-7&4\\-8&2&1\\ 3&3&-6 \end{array}\right)\,=\;\left(\begin{array}{rrr}\frac{2}{15}&\frac{7}{15}&-\frac{4}{15}\\ \frac{8}{15}&-\frac{2}{15}&-\frac{1}{15}\\ -\frac{3}{15}&-\frac{3}{15}&\frac{6}{15} \end{array}\right).