Question

Find the value of determinant :

`|(3, -4, 5),(1, 1, -2),(2, 3, 1)|`

Answer 1

`|(3, -4, 5),(1, 1, -2),(2, 3, 1)|`

= `3|(1, -2),(3, 1)| - (-4)|(1, -2),(2, 1)| + 5|(1, 1),(2, 3)|`

= 3 (1 + 6) + 4 (1 + 4) + 5 (3 - 2)

= 3 (7) + 4 (5) + 5 (1)

= 21 + 20 + 5

= 46.