Matthew S. answered • 03/25/20

PhD in Mathematics with extensive experience teaching Linear Algebra

a) Adding a scalar multiple of one row to another row does not change the determinant. So the matrix resulting from this operation has determinant -2

b) Multiplying a row by a scalar multiplies the determinant by that scalae. So the matrix resulting from this operation has determinant 3*(-2) = -6

c) Interchanging rows multiplies the determinant by -1. So the matrix resulting from this operation has determinant +2