Question

Sendo
A= I 9 7 I
I -4 -1 I

SENDO DETERMINATE É:


b) 16


c) 20


d) 50

Answer 1

A = |9 7|

|-4-1|

Det(A) = 9. (-1) - 7.(-4)

Det(A) = -9 + 28

Det(A) = 19

alternativa d) ✓

Answer 2

$\large{\begin{array}{l}\sf A=\begin{bmatrix}\sf9&\sf7\\\sf-4&\sf-1\end{bmatrix}\\\\\sf det\,A=(9\cdot(-1))-(7\cdot(-4))\\\sf det\,A=(-9)-(-28)\\\sf det\,A=-9+28\\\sf det\,A=19\end{array}}$