If (N = begin{pmatrix} 3 & 5 & -4 \ 6 & -3 & -5 \ -2 & 2 & 1 end{pmatrix}), find (|N|).
-
A.
65 -
B.
23 -
C.
17 -
D.
91
Correct Answer: Option C
Explanation
(begin{vmatrix} 3 & 5 & -4 \ 6 & -3 & -5 \ -2 & 2 & 1 end{vmatrix})
= (3(-3 – (-10)) – 5(6 – 10) + (-4)(12 – 6))
= (21 + 20 – 24)
= 17
There is an explanation video available below.