kak tolong nomer 15

jawab

C = A. B

[tex]C = \left[\begin{array}{ccc}-2&1\\-1&2\end{array}\right]\, \left[\begin{array}{ccc}1&0\\-1&2\end{array}\right]\, =\left[\begin{array}{ccc}-3&2\\-3&4\end{array}\right] \\ C^{-1}\, = \frac{1}{-3(4) +2(-3)}\left[\begin{array}{ccc}4&-2\\3&-3\end{array}\right] \,= \frac{1}{-6} \left[\begin{array}{ccc}4&-2\\3&-3\end{array}\right] \\ C^{-1}\, = \frac{1}{6}\left[\begin{array}{ccc}-4&2\\-3&3\end{array}\right] \,[/tex]