static void Main(string[] args)
{
Phanso t = new Phanso();
t.nhap(); t.hien();
Phanso t2 = new Phanso();
t2.nhap(); t2.hien();
Phanso t3 = new Phanso();
t3 = t.tong(t2); Console.WriteLine("Tong 2 phan so");; t3.hien();
t3 = t.tong2(5);
Console.WriteLine("tong phan so voi 1 so"); t3.hien();
t3 = t.hieu(t2);
Console.WriteLine("hieu 2 phan so"); t3.hien();
t3 = t.hieu2(5); Console.WriteLine("hieu ps voi 1 so"); t3.hien();
Console.ReadKey();
}