program giai_bac_2;
uses crt;
var a,b,c,d:integer;
{---nhap---}
procedure nhapso;
begin
write('Nhap a: '); readln(a);
write('Nhap b: '); readln(b);
write('Nhap c: '); readln(c);
end;
{---tinh-delta---}
procedure delta;
begin
d:=b*b-4*a*c;
writeln('delta la: ',d);
end;
{---Xet-delta---}
procedure xet_delta;
begin
if d<0 then write('Phuong trinh vo nghiem');
if d=0 then write('Phuong trinh co 1 nghiem kep: x1=x2= ',-b/(2*a):0:3);
if d>0 then
begin
writeln('Phuong trinh co 2 nghiem phan biet: ');
writeln('x1= ',(-b+sqrt(d))/(2*a):0:3);
writeln('x1= ',(-b-sqrt(d))/(2*a):0:3);
end;
end;
{---Chuong-trinh-chinh---}
BEGIN
clrscr;
nhapso;
delta;
xet_delta;
readln;
end.
