Program GIAI_PHUONG_TRINH_BACII;
Uses CRT;
Var a,b,c,D,x,x1,x2: real;
Begin
  Clrscr;
  Writeln('GIAI PHUONG TRINH BAC II: ');
  Writeln('-------------------------------------------');
  Write('Nhap he so a='); readln(a);
  Write('Nhap he so b='); readln(b);
  Write('Nhap he so c='); readln(c);
  If a=0 then
    If b=0 then
      If c=0 then
        Writeln('Phuong trinh co vo so nghiem')
      Else Writeln('Phuong trinh vo nghiem')
    Else Writeln('Phuong trinh co mot nghiem: x=',-c/b: 4: 2)
  Else
    Begin
      D:=b*b-4*a*c;
      If D=0 then Writeln('Phuong trinh co nghiem kep: x=',-b/(2*a): 4: 2)
      Else
        If D<0 then Writeln('Phuong trinh vo nghiem')
        Else
           Begin
             x1:=(-b-sqrt(D))/(2*a);
             x2:=(-b+sqrt(D))/(2*a);
             Writeln('Phuong trinh co 2 nghiem la x1= ',x1:4:2 ,' va x2= ',x2:4:2);
           End;
     End;
Readln
End.