câu 1:
uses crt;
var i,n,t:longint;
begin
clrscr;
write('Nhap n: ');readln(n);
t:=1;
for i:= 1 to n do t:=t*i;
writeln('Tich = ',t);
readln;
end.
câu 2
program bt;
uses crt;
var n,S,i:integer;
begin
clrscr;
writeln('hay nhap n: ');readln(n);
S:=0;
for i:=1 to n do
S:=S+(i*i);
writeln('tong binh phuong cua day so la: ',S);
readln;
end.