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;

ReadlnEnd.

var a, b, c : real;

begin

readln(a, b, c);

dt := b * b - 4 * a * c;

if dt >0 then

begin

if dt = 0 then writeln('x = ', (-b / (2 * a)):2:2)'

if dt < 0 then writeln(' Phương trinh vo nghiem');

end;

writeln('x1 =', ((- b + sqrt(dt))/(2 * a)):2:2);

writeln('x2 =', ((- b - sqrt(dt))/(2 * a)):2:2);

readln;

end.