Let Δ = Applying Elementary Row Transformations R 2 → R 2 – 2R 1 Δ = R 3 → R 3 – 3R 1 Δ = R 3 → R 3 – 3R 2 Δ = Expanding Along C 1 , we have Δ = 1 (1 × 1 – 0 × (2 + p)) – 0 + 0 Δ = 1 – 0 Δ = 1 Hence, the given result is proved

Prove that

Let Δ =

Applying Elementary Row Transformations

R₂→ R₂ – 2R₁

Δ =

R₃→ R₃ – 3R₁

Δ =

R₃→ R₃ – 3R₂

Δ =

Expanding Along C₁, we have

Δ = 1 (1 × 1 – 0 × (2 + p)) – 0 + 0

Δ = 1 – 0

Δ = 1

Hence, the given result is proved