If the determinant of a 4 times 4 matrix A is det A 3 and th

If the determinant of a 4 times 4 matrix A is det (A)= 3, and the matrix D is obtained from A by adding, 7 times the fourth row to the first, then det (D) =

Solution

From set of theorems on how changes to a matrix affect the determinant.

One of them is Adding a multiple of one row to another has no effect on the determinant.

hence det(D) = det(A) = 3