public class cuadratica {

    static public void main(String args[])
    {

      double A=9, B=6, C=4;
      double X1=0, X2=0, G=0, I=0, D=0;

      D=(B*B-(4*A*C));

      if (D>0)
      {
        // si las raices son positivas

        X1=(-B+Math.sqrt(D))/(2*A);
        X2=(-B-Math.sqrt(D))/(2*A);
        System.out.printf("X1 = %f\n", X1);
        System.out.printf("X2 = %f\n", X2);
      }
      else
      {
        // si las raices son negativas
        G=-B/(2*A);
        I=Math.sqrt(-D)/(2*A);
        System.out.printf("X1 = %f, %f j\n", G, I);
        System.out.printf("X2 = %f, %f j\n", G, -I);
      }

    }
}