Question

The value of the determinant $\left|\begin{array}{ccc}1& 8& 0\\ 7& 1& 5\\ 3& 4& 2\end{array}\right|$ is

Answer 1

Given,

$\left|\begin{array}{ccc}1& 8& 0\\ 7& 1& 5\\ 3& 4& 2\end{array}\right|$

Expanding the determinant along first row, we get

$=1(2-20)-8(14-15)+0$

$=-18+8$

$=-10$