Let Δ=∣∣​0−ab​a0c​−b−c0​∣∣​ Taking (-1) common from all the 3 rows. Again, interchanging rows and columns, we haveΔ=−∣∣​0−ab​a0c​−b−c0​∣∣​ Δ=−Δ Which shows that, 2Δ=0 or Δ=0 . Proved.