From A2−4A+2I=O: characteristic equation is λ2−4λ+2=0.
For A: α+2=4⇒α=2.
From B2−3B+I=O: characteristic equation is λ2−3λ+1=0.
For B: β+1=3⇒β=2.
A3=14A−8I, B3=8B−3I.
A3−B3=14A−8B−5I=[156207].
det(A3−B3)=105−120=−15.
For 2×2 matrix: det(adj(M))=det(M).
(det(adj(A3−B3)))2=225.