Row Operation On determinants:
R1 -> cR1 - aR3
Can be split into 2 operations:
(1) first, follow by (2)

(1) R1 -> cR1
Scalar Multiplication of row
Increases determinant by the scalar factor,
Hence new determinant scaled by c

(2) R1 -> R1 - aR3
Addition/subtraction of row does not affect determinant. Hence the determinant remains the same as (1).

:. Determinant scaled up by c from original matrix //