a/
Var
n,i:Integer; S:real;
BEGIN
Write(‘Nhap so tu nhien n=');Readln(n);
s:= 0; d:=1;
For i:=1 to n do begin s:=s+ d/i ; d:=-d; end;
Write(‘Tong cac so la s=’,s);
Readln
END.
b/
Var
n,i:Integer;
s:Real;
BEGIN
Write(‘Nhap so tu nhien n=');Readln(n);
While ((n<=5) OR (n>100) do
Begin
Write(‘Nhap lai n thoa man 5 < n <=100, n = ');Readln(n);
end;
s:=0;
For i:=1 to n do s:=s+i*(i+1)/((i+2)*(i+3));
Write(‘tong la s=’,s:4:3);
Readln
END.
