Question

qual a determinante(URGENTE)pra hoje
7 -4 3
1 -1 0
5 -4 1​
a)0
b)8
c)-38
d)19

Answer 1

Vamo resolver o determinante utilizando a Regra de Sarrus.

Passo a passo:

$\left[\begin{array}{ccc}7&-4&3\\1&-1&0\\5&-4&1\end{array}\right] \\ \\ \\ \\ \begin{array}{ccc}7&-4&3\\1&-1&0\\5&-4&1\end{array}\begin{array}{ccc}7&-4\\1&-1\\5&-4\end{array}$

$\left[(7\cdot-1\cdot1)+(-4\cdot 0\cdot 5)+(3\cdot 1\cdot-4)\right]~-~\left[(3\cdot-1\cdot5)+(7\cdot0\cdot -4)+(-4\cdot 1\cdot1)\right]=$

$\left[-7+0+(-12)\right]~-~\left[-15+0+(-4)\right]=\\ \\ \left[-7-12\right]-\left[-15-4\right]=\\ \\ -19-\left[-19\right]=\\ \\ -19+19=\\ \\~~ 0$

Determinante é zero.

:)