C++一元二次方程组

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
   double a, b, c;
   double x, x1, x2;
   double delta;
   cin >> a >> b >> c;

    if(a == 0)
    {
        if(b == 0)
        {
            cout << "Can't" << endl;
        }
        else
        {
            x = -c / b;
            cout << "x = " << x ;
        }
    }
    else
    {
         delta = b * b - 4 * a * c;
         if(delta >= 0)
         {
             delta = sqrt(delta);
             x1 = (-b + delta) / 2 * a;
             x2 = (-b - delta) / 2 * a;
             cout << "x1 = " << x1 << endl;
             cout << "x2 = " << x2 << endl;
         }
         else
         {
             delta = sqrt(-delta);
             x1 = -b / 2 / a ;
             x2 = delta / 2 /a;
             cout << "x1 = " << x1  << "+j"<< endl;
             cout << "x2 = " << x1 << "-j" << x2 << endl;
         }
    }




    return 0;
}