program sksk ;
uses crt;
var a, b, c, dt : real;
begin
clrscr;
write('nhap lan luot he so a, b, c :'); readln(a, b, c);
dt :=b*b - 4*a*c;
if dt > 0 then
begin
writeln('phuong trinh co 2 nghiem phan biet la : ');
writeln('nghiem x1 =', (-b + sqrt(dt))/(2*a):8:2);
writeln('nghiem x2 =', (-b - sqrt(dt))/(2*a):8:2);
end
else
if dt = 0 Then writeln('phương trinh co 1 nghiem kep la : ', (-b/(2*a)):8:2 )
else
if dt < 0 then writeln(' Phương trinh vo nghiem');
readln
end.

program giai_phuong_trinh_bac_2;
uses crt;
var a, b, c, x1, x2, x, dt : real;
begin
clrscr;
write('nhap lan luot he so a, b, c :'); readln(a, b, c);
dt :=b*b - 4*a*c;
if dt >0 then
begin
writeln('phuong trinh co 2 nghiem phan biet la : ');
x1 := (-b + sqrt(dt))/(2*a);
x2 := (-b - sqrt(dt))/(2*a);
writeln('nghiem x1 =', x1:8:2);
writeln('nghiem x2 =', x2:8:2);
end
else
if dt = 0 Then
begin
x:=(-b/(2*a));
writeln('phương trinh co 1 nghiem kep la : ', x:8:2 );
x:=(-b/(2*a));
end
else
writeln(' Phương trinh vo nghiem');
readln;
end.