[2−134121−31]
= 2[(1 x 1) - (2 x -3)] - (-1)[(4 x 1) - (2 x 1)] + 3[(4 x -3) - (1 x 1)]= 2(1 - (-6)) + 1(4 - 2) + 3(-12 - 1)= 2(1 + 6) + 1(2) + 3(-13)= 2(7) + 1(2) + 3(-13)= 14 + 2 - 39∴ |D| = -23