λ = 4.6 (slider from -15 to 15, step 0.1)
a: (λ - 1.0) * x + (2.0 * λ + 1.0) * y + λ + 5.0 = 0.0
b: (2.0 * λ - 1.0) * x + (λ - 2.0) * y + λ - 3.0 = 0.0
A = Intersect(b, a)