2 câu trả lời
program bai_giai;
uses crt;
var n,i,s:longint;
begin
clrscr;
write('nhap n:');readln(n);
s:=0;
for i:=1 to n do s:=s+i;
write('s=',s);
readln
end.
program bai_giai;
uses crt;
var n,i,s:longint;
begin
clrscr;
write('nhap n:');readln(n);
s:=0;
for i:=1 to n do s:=s+i;
write('s=',s);
readln
end.