Answer:
The value of det (3A) is -108.
Explanation:
If M is square matrix of order n x n, then

Let as consider a matrix A or order 3 x 3. Using the above mentioned property of determinant we get

We need to find the value of det(3A).


It is given that the det(A)= -4. Substitute |A|=-4 in the above equation.


Therefore the value of det (3A) is -108.