EventHandler delegate and EventHandler event

using System;
namespace ConsoleApp1
{
    class Car
    {
        //subscribed delegates
        public EventHandler eventHandlerDelegate;
        private int speed;
        public void SpeedMe()
        {
            speed++;
            if (speed > 2)
                if(eventHandlerDelegate != null)
                    eventHandlerDelegate.Invoke(this, new EventArgs());
        }
    }
    class Truck
    {
        //subscribed events
        private int speed;
        public event EventHandler bumEvent;
        public void SpeedMe()
        {
            speed++;
            if (speed > 2)
                bumEvent?.Invoke(this, new EventArgs());
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            //delegates
            Car car1 = new Car();          
            car1.eventHandlerDelegate += Bum;

            car1.SpeedMe();
            car1.SpeedMe();
            car1.SpeedMe(); //"bum car 1,2"

            //events
            Truck truck1 = new Truck();
            truck1.bumEvent += new EventHandler(Bum);

            truck1.SpeedMe();
            truck1.SpeedMe();
            truck1.SpeedMe(); //"bum truck 1,2"
        }
        private static void Bum(object o, EventArgs arg) { Console.WriteLine("bum"); }
    }
}

Car car1 = new Car();                      
car1.eventHandlerDelegate += (o, e) => { Console.WriteLine("bum2"); }; // zrobi że będzie bum2
car1.eventHandlerDelegate = Bum; // zrobi, ze będzie również bum zwykłe

car1.SpeedMe();
car1.SpeedMe();
car1.SpeedMe(); //"bum car 1,2"

Car car1 = new Car();                      
car1.eventHandlerDelegate += Bum;
car1.eventHandlerDelegate.Invoke(null, null);
    // haha, odpaliłem, że zdarzenie odpaliło, a ono nie nastąpiło tak naprawdę!

truck1.bumEvent += Bum;

public EventHandler eventHandlerDel;	

	.field public class [mscorlib]System.EventHandler eventHandlerDel

public event EventHandler eventHandlerEv;

	 .event [mscorlib]System.EventHandler eventHandlerEv
	  {
		.addon instance void ConsoleApp1.Truck::add_eventHandlerEv(class [mscorlib]System.EventHandler)
		.removeon instance void ConsoleApp1.Truck::remove_eventHandlerEv(class [mscorlib]System.EventHandler)
	  } // end of event Truck::eventHandlerEv
	} // end of class ConsoleApp1.Truck

 public int Speed { get; set };
 public event EventHandler BumEvent;

private int speed;
private EventHandler bumEvent;

public int Speed
{
    get
    {
        return speed;
    }
    set
    {
        speed = value;
    }
}


public event EventHandler BumEvent
{
    add
    {
        bumEvent += value;
    }
    remove
    {
        bumEvent -= value;
    }
}

using System;

namespace ConsoleApp25
{
    delegate int Dzialanie(int x1, int x2);

    class Program
    {
        private static Dzialanie dz;
        static void Main(string[] args)
        {

            add_dz(new Dzialanie(Dodaj));
            add_dz(new Dzialanie(Dodaj));
            Console.WriteLine(dz(10, 10));

            remove_dz(new Dzialanie(Dodaj));
            Console.WriteLine(dz(10, 10));

            add_dz(new Dzialanie(Odejmij));

            Console.WriteLine(dz(10, 10));

        }

        public static int Dodaj(int x1, int x2)
        {
            return x1 + x2;
        }

        public static int Odejmij(int x1, int x2)
        {
            return x1 - x2;
        }

        public static void add_dz(Dzialanie value)
        {
            Dzialanie loc0, loc1, loc2;
            loc0 = dz;
            do
            {
                loc1 = loc0;
                loc2 = (Dzialanie)System.Delegate.Combine(loc1, value);
                loc0 = System.Threading.Interlocked.CompareExchange<Dzialanie>(ref dz, loc2, loc1);
            } while (!Object.ReferenceEquals(loc0, loc1));

        }

        public static void remove_dz(Dzialanie value)
        {
            Dzialanie loc0, loc1, loc2;
            loc0 = dz;
            do
            {
                loc1 = loc0;
                loc2 = (Dzialanie)System.Delegate.Remove(loc1, value);
                loc0 = System.Threading.Interlocked.CompareExchange<Dzialanie>(ref dz, loc2, loc1);
            } while (!Object.ReferenceEquals(loc0, loc1));

        }

    }
}

using System;

namespace ConsoleApp25
{
    delegate int Dzialanie(int x1, int x2);

    class Program
    {

       public static event Dzialanie dz;
        static void Main(string[] args)
        {

            dz += Dodaj;
            dz += Dodaj;
            Console.WriteLine(dz(10, 10));

            dz -= Dodaj;
            Console.WriteLine(dz(10, 10));

            dz += Odejmij;

            Console.WriteLine(dz(10, 10));

        }

        public static int Dodaj(int x1, int x2)
        {
            return x1 + x2;
        }

        public static int Odejmij(int x1, int x2)
        {
            return x1 - x2;
        }

        

    }
}