Ответ:
1)
program NewProgram;
var n:integer;
result:real;
begin
Readln(n);
result := 0;
Repeat
result += (1+n)/(2+sqr(n));
n -= 1;
Until n
Writeln(result);
end.
2)
program NewProgram;
var n:integer;
result:real;
begin
Readln(n);
result := 0;
while n > 0 do
begin
result += (1+n)/(2+sqr(n));
n -= 1;
end;
Writeln(result);
end.
3)
program NewProgram;
var n, i:integer;
result:real;
begin
Readln(n);
result := 0;
for i:=1 to n do
result += (1+i)/(2+sqr(i));
Writeln(result);
end.