using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Tim nghiem cua phuong trinh ax^2 + bx + c = 0 (a <> 0)");

        double a, b, c;

        Console.Write("Nhap a: ");

        a = double.Parse(Console.ReadLine());

        Console.Write("Nhap b: ");

        b = double.Parse(Console.ReadLine());

        Console.Write("Nhap c: ");

        c = double.Parse(Console.ReadLine());

​

        double delta = b * b - 4 * a * c;

​

        if (delta < 0)

        {

            Console.WriteLine("Phuong trinh vo nghiem");

        }

​

        if (delta == 0)

        {

            double x = -b / (2 * a);

            Console.WriteLine("Nghiem cua phuong trinh la:");

            Console.WriteLine($"x = {x}");

        }

​

        if (delta > 0)

        {

            double x1, x2;

            x1 = (-b + Math.Sqrt(delta)) / (2 * a);

            x2 = (-b - Math.Sqrt(delta)) / (2 * a);

            Console.WriteLine("Nghiem cua phuong trinh la:");

            Console.WriteLine($"x1 = {x1}");

            Console.WriteLine($"x2 = {x2}");

        }

    }

}