Question

Evaluate `|(1,x,y),(1,x+y,y),(1,x,x+y)|`

Answer 1

Let, Δ = `|(1,x,y),(1,x+y,y),(1,x,x+y)|` 

Applying R₂ → R₂ − R₁ and R₃ → R₃ − R₁, we get

= `|(1,x,y), (0,y,0), (0, 0,x)|`

= 1 × y × x

= xy