uses crt;
var a,b:extended;
{---a=0---}
procedure TH1;
begin
writeln('PT co vo so nghiem');
end;
{---------}
procedure TH1_1;
begin
writeln('PT vo nghiem');
end;
{---b<>0---}
procedure TH2;
begin
writeln('PT co 1 nghiem duy nhat: x=',-b/a:0:2);
end;
{---Chuong-trinh-chinh---}
BEGIN
clrscr;
write('Nhap a,b: '); readln(a,b);
if a=0 then if b=0 then TH1
else if (a=0) and (b<>0) then TH1_1
else TH2;
readln;
END.