uses crt;
var a, b, c, dt : real;
begin
clrscr;
write('nhap he so a, b, c :'); readln(a, b, c);
dt := b * b - 4 * a * c;
if a <> 0 then
begin
if dt > 0 then
begin
writeln('nghiem x1 = ', ((- b + sqrt(dt))/(2 * a)):2:2);
writeln('nghiem x2 = ', ((- b - sqrt(dt))/(2 * a)):2:2);
end
else if dt = 0 then writeln('x = ', (-b / (2 * a)):2:2)
else writeln(' Phương trinh vo nghiem');
end;
readln;
end.