using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        double x, Y;

        Console.WriteLine("Nhap vao 1 so x bat ky: ");

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

        Console.WriteLine("Cho biet ket qua cua da thuc Y = 3*(x*x) + 4x - 7 ");

        Y = 3*(x*x) + 4 * x - 7 ;

        Console.WriteLine("Ket qua cua da thuc Y  = 3( "+x+" x "+x+") + 4 x "+x+" - 7 = "+Y+" ");

        Console.WriteLine("Dung khong ta ? ");

        Console.ReadLine();

    }

}