Question

B= [-18    3]

[4       1 ]

What is the determinant of B?

A. −27
B. 30
C. −30
D. –6

Answer 1

Det=(-18x1)-(4x3)
=-30
so the answer is C

Answer 2

Option C.

Explanation:

The given matrix is B =
`\left[\begin{array}{ccc}-18&3\\4&1\end{array}\right]`

We have to find the determinant of the given matrix.

In a matrix given in the form of
`\left[\begin{array}{ccc}a&b\\c&d\end{array}\right]`

Determinant of the matrix is represented by ad - bc

By this rule,

Determinant B = (-18)×1 - 3×4

= -18 - 12

= -30

Therefore, option C. -30 will be the answer.