using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        int[] items1 = new int[] {10,20,30,40};

        int[] items2 = new int[] {20,50,80,100};

        var resultItems = items1.Zip(items2, (i1, i2) => i2 - i1).ToArray();

        Console.WriteLine(string.Join(", ", resultItems));

    }

}