2) Ache .

2. Ache $x, y, z, w$ se $\left[\begin{array}{ll}x & y \\ z & w\end{array}\right]\left[\begin{array}{ll}2 & 3 \\ 3 & 4\end{array}\right]=\left[\begin{array}{ll}1 & 0 \\ 0 & 1\end{array}\right]$.