mình làm câu 2 thôi nhá :()
câu 2:
uses crt;
var a: array[1..100] of integer;
i,n: integer;
begin
clrscr;
Write ('nhap n: '); readln (n);
for i:=1 to n do
begin
write ('nhap phan tu thu ',i,': '); readln (n);
end;
writeln ('cac phan tu am: ');
for i:=1 to n do if a[i]<0 then write (a[i]:3);
readln;
end.