Fie matricele A= [tex](\left \ {{1 2} \atop {01}} \right. )[/tex] , B= [tex](\left \ {{10} \atop {2}} \right. \left \ {{20} \atop {3}} \right. )[/tex] din [tex]M_{2}[/tex] (IR).
a) Aratati ca det(A)-det(B)=11
b) Demonstrati ca A+A²+A³=3A²
c) Aflati x∈[tex]M_{2}[/tex] (IR), stiind ca A²·x=B