If A=is not invertible then λ=?
=
│A│=0
1(2 x 1 – 5 x1) - (1 x 1 – 5 x 2) + 2 ( 1x1 – 2x 2) = 0
-3+9 λ -6 = 0
9 λ = 9
λ = 1