Question

Qual o determinante que representa a matriz quadrada
1 0 3
4 0 -1
2 8 6

Answer 1

$\left|\begin{matrix} 1&0&3\\ 4&0&-1\\ 2&8&6 \end{matrix}\right| = (-1)^{3+2}\cdot 8 \left|\begin{matrix}1&3\\4&-1\end{matrix}\right|=-8[(1)(-1)-(3)(4)]=-8(-13)\\ \\ \\ \boxed{\left|\begin{matrix} 1&0&3\\ 4&0&-1\\ 2&8&6 \end{matrix}\right|=104}$