#include <iostream>
using namespace std;
int main()
{
	double a, b, c, delta, x, x1, x2;
	cout << "Nhap a: ";
	cin >> a;
	cout << "Nhap b: ";
	cin >> b;
	cout << "Nhap c: ";
	cin >> c;
	if (a != 0)
	{
		delta = b * b - 4 * a * c;
		if (delta > 0)
		{
			x1 = (-b + sqrt(delta)) / (2 * a);
			x2 = (-b - sqrt(delta)) / (2 * a);
			cout << "Nghiem thu nhat la " << x1 << endl;
			cout << "Nghiem thu hai la " << x2 << endl;
		}
		else
		{
			if (delta == 0)
			{
				cout << "Phuong trinh co nghiem kep la: " << (-b) / (2 * a) << endl;
			}
			else
			{
				cout << "Phuong trinh vo nghiem";
			}
		}
	}
	else
	{
		if (b != 0) cout << "Nghiem cua phuong trinh la: " << -c / b;
		else
		{
			if (c == 0) cout << "Phuong trinh vo so nghiem";
			else cout << "Phuong trinh vo nghiem";
		}
	}
	return 1;
}