кто знает как решить задачки

Program xxx;
uses crt;
Var n:integer;
      S:real;
begin
clrscr;
Write ('n=');
Readln (n);
s:=0;
for n=1 to 5 do
s:=s+1/(4*exp(n));
Writeln ('s=',s:4:2);
Readln
end.

Program xxx;
uses crt;
Var n,x:integer;
      S:real;
begin
clrscr;
Write ('n=');
Readln (n);
Write ('EPS=');
Readln (x);
S:=0;
for n:=1 to x do
s:=s+((-1)*exp(n))/2*n*(n+1);
Writeln ('s=',s:4:2);
Readln
end.

var
  n,i,j,k:integer;
begin
  write('n=');
  readln(n);
  for i:=1 to n do 
    begin
    k:=0; 
      if (n mod i=0) then 
        begin
        for j:=1 to i do if (i mod j=0) then k:=k+1; 
        if k<=2 then writeln(i); 
        end;
      end;
  readln;
end.

var
  X:integer;
  y:real;
begin
  write('x=');
  readln(x);
if x<=-3 then y:=sqr(-x)*sqr(-x)+x*x*x-1;
if (x>-3) and (x<=-1) then y:=x+1;
if x>-1 then y:=sin(-x);
Writeln ('y=',y:4:2);
  readln;
end.