[tex]\left(\begin{array}{ccc}-3&1\\2&-2\end{array}\right) +x \left(\begin{array}{ccc}0&1\\1&0\end{array}\right)= \left(\begin{array}{ccc}-3&1\\2&-2\end{array}\right) +\left(\begin{array}{ccc}0&x\\x&0\end{array}\right)= [/tex]=[tex] \left(\begin{array}{ccc}-3&1+x\\2+x&-2\end{array}\right)[/tex]
det ( A + xB)= [tex] \left[\begin{array}{ccc}-3&1+x\\2+x&-2\end{array}\right] =[/tex]