Diketahui matriks
A = ⎧2 1⎫ dan B = ⎧8 -4⎫
⎩-4 3⎭ ⎩5 7⎭
Pembahasan:
B – 2A = ⎧8 -4⎫ _ ₂⎧2 1⎫
⎩5 7⎭ ⎩-4 3⎭
= ⎧8–4 –4–2⎫
⎩5+8 7–6⎭
= ⎧4 –6⎫
⎩13 1⎭
det(B – 2A) = 4 – 13(–6)
= 4 + 78
= 82