If $A=\begin{bmatrix}1 & 1 & -2\\2 & 1 & -3\\5 & 4 & -9 \end{bmatrix}$, then |A| is equal to
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 0
$A=\begin{bmatrix}1 & 1 & -2\\2 & 1 & -3\\5 & 4 & -9 \end{bmatrix}$
$C_3→C_3+C_1+C_2$
$|A|=\begin{bmatrix}1 & 1 & 0\\2 & 1 & 0\\5 & 4 & 0\end{bmatrix}$
$⇒|A|=0$