If the determinant of a 44 matrix A is detA2 and the matrix

If the determinant of a 4×4 matrix A is det(A)=2, and the matrix B is obtained from A by multiplying the third row by 9, then det(B)=

Solution

If a scalar is multiplied to any row of a matrix , then the scalar is also multiplied with the det value of the initial matrix.

Matrix B is obtained by multiplying 9 with third row of matrix A.

So, det (B) = 9 x det(A) = 9 x 2 = 18

det(B) = 18