Ответ:Корни 3 и 12: x ∈ (−∞; 3] ∪ [12; +∞).Корни −6 и 5/2: z ∈ (−∞; −6) ∪ (5/2; +∞).Нули −4, 6/5 и 5/2: x ∈ (−∞; −4) ∪ (6/5; 5/2).