Question

Calcule?
|2 3 1|
|1 2 0|
|4 -1 1|

Answer 1

Basta aplicar a regra de Sarrus:

|2 3 1| 2 3
|1 2 0| 1 2
|4 -1 1| 4 -1

detA = 2.2.1 + 3.0.4 + 1.1.(-1) - 1.2.4 - 2.0.(-1) - 3.1.1

detA = 4 + 0 - 1 - 8 - 0 - 3

detA = 4 - 12

detA = -8