using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var list1 = new List<int>() { 1, 2, 3, 4, 5}; 

        var list2 = new List<int>() { 3, 4, 5, 6, 7 };

​

        var result = list1.Select((x, i) => x - list2[i]).ToList();

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

    }

}