Question

If the matrix A is such that $\left[\begin{array}{c}2\\ -4\\ 7\end{array}\right]$ $\left[\begin{array}{ccc}1& 9& 5\end{array}\right]$

then the determinant of A is equal to

• A. 0

Answer 1

The correct option is A 0
$A=\left[\begin{array}{c}2\\ -4\\ 7\end{array}\right]$ $\left[\begin{array}{ccc}1& 9& 5\end{array}\right]$ = $$\left[\begin{array}{ccc}2& 18& 10\\ -4& -36& -20\\ {}^{}7& 63& 35\end{array}\right]$$
$\Rightarrow$ |A| = 0