Pierwiastki Pq: x³ +px +q = 0 ma trzy pierwiastki x1,x2,x3 x1=x2=x3+9 dla : a) p=27, q = 2p b) p = −12, q = 16 c) p = 27, q = −54 d) p = −27, q = 54

ICSP: x₁ + x₂ + x₃ = 0 x₁ + x₁ + x₁ − 9 = 0 3x₁ = 9 x₁ = 3 x₂ = 3 x₃ = −6 p = x₁x₂ + x₂x₃ + x₁x₃ = ... q = −x₁x₂x₃ = ...