Of course you can use Linq:
var s = new string[] { "a", "b", "c" };
var s2 = s.Concat(new string[] { "V" }).ToArray();
or for blank array
var s = new string[] { "a", "b", "c" };
var s2 = s.Concat(new string[5]).ToArray();
Other solutions also work, and probably faster, but if you are combining arrays, Linq is probably better.