program btsydn;

uses crt; 

  var a, b, c, d: integer;

begin

        clrscr;

        write('Nhap a = '); readln(a);

        write('Nhap b = '); readln(b);

        write('Nhap c = '); readln(c);

        if (a=0) and (b=0) and (c=0) then write('Phuong trinh vo so nghiem');

        if (a=0) and (b=0) and (c<>0) then write('Phuong trinh vo nghiem');

        if (a=0) and (b<>0) then write('Phuong trinh co nghiem: x = ', -c/b:2:1);

        d:=0

        if (a<>0) then

        begin

             d:=b*b-4*a*c;

             if d<0 then write('Phuong trinh vo nghiem');

             if d=0 then write('Phuong trinh co nghiem khep: x1 = x2 = ', -b/2*a:2:1);

             if d>0 then write('Phuong trinh co 2 nghiem: x1 = ', (-b-sqrt(a))/(2*a):2:1, ' x2 = ', (-b-sqrt(d))/(2*a):2:1);

        end;

        readln

end.

uses crt;

var a,b,c,d,x:real;

begin

 clrscr;

writeln('nhap lan luot a, b, c');readln(a,b,c);

 d:=(b*b)-(4*a*c);

if d<0 then writeln('phuong trinh vo nghiem')

 else if d=0 then writeln(-b/(2*a))

  else begin

  x:=(-b-sqrt(d))/(2*a);

 writeln(x);

 x:=(-b+sqrt(d))/(2*a);

 writeln(x);

end;

readln;

end.