using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Giai phuong trinh bac hai\n");

​

            Console.Write("Nhap gia tri cua a: ");

            a = Convert.ToInt32(Console.ReadLine());

            Console.Write("\nNhap gia tri cua b: ");

            b = Convert.ToInt32(Console.ReadLine());

            Console.Write("\nNhap gia tri cua c: ");

            c = Convert.ToInt32(Console.ReadLine());

​

            x = b * b - 4 * a * c;

            if (x == 0)

            {

                Console.Write("Phuong trinh co mot nghiem duy nhat.\n");

                x1 = -b / (2.0 * a);

                x2 = x1;

                Console.Write("Nghiem duy nhat cua phuong trinh la = {0}\n", x1);

            }

            else if (x > 0)

            {

                Console.Write("Phuong trinh co hai nghiem thuc phan biet\n");

​

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

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

​

                Console.Write("Nghiem thu nhat: x1 = {0}", x1);

                Console.Write("Nghiem thu nhat: x2 = {0}", x2);

            }

            else

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

​

​

​

​

​

​

​

            Console.ReadKey();

    }

}