Question

(pfv) calcule as determinantes

Answer 1

a) Cortamos a primeira coluna e a primeira linha, depois multiplicamos o determinante pelo primeiro termo, veja:
$\left[\begin{array}{ccc}3&5&0\\-2&1&6\\4&2&-2\end{array}\right] = \left[\begin{array}{ccc}1&6\\2&-2\\\end{array}\right] =1*(-2)-2*(-2)=2\\\\\\D=2*3=6$


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b) $\left[\begin{array}{ccc}3&6&9\\4&7&10\\5&8&11\end{array}\right] = \left[\begin{array}{ccc}7&10\\8&11\\\end{array}\right] =7*11-10*8= -3\\\\D=-3*3=-9$



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Forte abraço!