Let Δ1=∣∣
∣∣a1b1c1a2b2c2a3b3c3∣∣
∣∣ and
Δ2 =∣∣
∣
∣∣α1β1γ1α2β2γ3α3β3γ3∣∣
∣
∣∣, and Δ1×Δ2 can be expressed as the sum of n determinants, then n=
27
Δ1×Δ2 is 3×3 determinant in which every element is sum of three terms.
⇒ It can be written as sum of
3×3×3=27 determinants