Adamowe zagadki

#include <iostream>

using namespace std;

int main() {

    cout << "*************************************************" << endl;
    cout << "*  Pierwiastki rownania kwadratowego   *" << endl;
    cout << "*      ax ^ 2 + bx + c = 0     *" << endl;
    cout << "*************************************************" << endl << endl;

    double a{}, b{}, c{};

    cout << "Podaj a = ";
    cin >> a;
    cout << "Podaj b = ";
    cin >> b;
    cout << "Podaj c = ";
    cin >> c;

    double delta{}, x1{}, x2{};
    delta = b * b - 4.0 * a*c;

    if (delta > 0) {
        cout << "Istnieja dwa pierwiastki tego rownania:" << endl;
        x1 = (-b - sqrt(delta)) / 2.0 * a;
        x2 = (-b + sqrt(delta)) / 2.0 * a;
        cout << "x1=" << x1 << "    " << "x2=" << x2 << endl;
    }
    else if (delta == 0) {
        cout << "Istnieje tylko jeden pierwiastek:" << endl;
        x1 = -b / (2.0 * a);
        cout << "x0=" << x1 << endl;
    }
    else cout << "Nie istnieja zadne pierwiastki tego rownania!!!" << endl << endl;
    system("pause");
return  0;
}