Diketahui
A = ⎡1 -3⎤ , B = ⎡-2 0⎤ , dan C = ⎡3 -1⎤
⎣-2 4⎦ ⎣1 3⎦ ⎣1 -2⎦
Pembahasan:
D = –2A + B – C
D = –2 ⎡1 -3⎤ ₊ ⎡-2 0⎤ _ ⎡3 -1⎤
⎣-2 4⎦ ⎣1 3⎦ ⎣1 -2⎦
D = ⎡-2 6⎤ ₊ ⎡-2 0⎤ _ ⎡3 -1⎤
⎣4 -8⎦ ⎣1 3⎦ ⎣1 -2⎦
D = ⎡-2 6⎤ ₊ ⎡-2 0⎤ _ ⎡3 -1⎤
⎣4 -8⎦ ⎣1 3⎦ ⎣1 -2⎦
D = ⎡-7 7⎤
⎣4 -3⎦
Maka determinan matriks D = ad – bc
D = (–7) × (–3) – 7 × 4
= 21 – 28
= –7