prima coloana o inmultesti cu -2 si o aduni la a doua, prima coloana o inmultesti cu -3 si o aduni la a treia[tex] \left[\begin{array}{ccc}1&0&0\\4&-3&-6\\7&-6&-12\end{array}\right] =
\left[\begin{array}{ccc}-3&-6\\-6&-12\end{array}\right] =48-36=12[/tex]
