SoftUni - 4.6* Quadratic Equation

//Write a program that reads the coefficients a, b and c of a quadratic equation ax2 + bx + c = 0 and solves it (prints its real roots).

using System;

class QuadraticEq
{
    static void Main()
    {
        Console.Write("Enter a= ");
        double a = double.Parse(Console.ReadLine());

        Console.Write("Enter b= ");
        double b = double.Parse(Console.ReadLine());

        Console.Write("Enter c= ");
        double c = double.Parse(Console.ReadLine());

        double D = (b * b) - (4 * a * c);

        if (D < 0)
        {
            Console.WriteLine("no real roots");
        }
        else if (D == 0)
        {
            double x = -b / (2 * a);
            Console.WriteLine("x1 = x2 = " + x);
        }
        else
        {
            double x1 = (-b - Math.Sqrt(D))/ (2 * a);
            Console.WriteLine("x1 = " + x1);

            double x2 = (-b + Math.Sqrt(D))/ (2 * a);
            Console.WriteLine("x2 = " + x2);
        }
    }
}