= -2[(-1)(2) − (-8)(4)] − 5[(3)(2) − (-8)(-1)] + 4[(3)(4) − (-1)(-1)]

= -2(30) − 5(-2) + 4(11)

= -60 + 10 + 44

= -6

Here, we are expanding by the first column. We can do the expansion by using the first row and we will get the same result.