MÌNH ĐÃ GIẢI HẾT CHO BẠN RỒI

1)
uses crt;
var a, b, c: integer;
begin
clrscr;
 write('nhap a, b, c: '); readln(a, b, c);
         if (a>b) and (a>c) then 
  writeln('so ',a,' lon nhat')
          else if (b>a) and (b>c) then
  writeln('so ',b,' lon nhat')
     else if (c>a) and (c>b) then
  writeln('so ',c,' lon nhat')
     else if (a=b) and (b=c) then
  writeln('3 so bang nhau');
readln;
end.
2)
uses crt;
var n, s, i: word;
begin
clrscr;
 write('nhap n: '); readln(n);
  for i:=1 to n do
  s:=s+i;
 writeln('tong s la: ',s);
readln;
end.
3)
uses crt;
var n, p, i: word;
begin
clrscr;
 p:=1;
 write('nhap n: '); readln(n);
  for i:=1 to n do
  p:=p*i;
 writeln('tich p la: ',p);
readln;
end.
4)
uses crt;
var n, s, i: word;
begin
clrscr;
 write('nhap n: '); readln(n);
  for i:=1 to n do
   s:=2*i-1;
 writeln('tong s la: ',s);
readln;
end.
5)
uses crt;
var i, a, d: integer;
begin
clrscr;
 for i:=1 to 5 do begin
  write('a',i,'='); readln(a);
      if (a<0) then inc(d);
   end;
 writeln('co ',d,' so am trong day')
readln;
end.
6)
uses crt;
var i, a, s: integer;
begin
clrscr;
 for i:=1 to 5 do begin
  write('a',i,'='); readln(a);
       if (a mod 2<>0) then 
  s:=s+a;
 writeln('tong cac so le trong day: ',s);
readln;
end.
7)
uses crt;
var a, i, d, s: integer;
begin
clrscr;
 for i:=1 to 5 do begin 
  write('a',i,'='); readln(a);
   inc(d);
  if (a=7) then s:=d;

    end;
  if (a>0) then writeln('so 7 xuat hien o ',s)
  else writeln('so 7 khong xuat hien');
readln;
end.
8)
uses crt;
var a, b, c, d, x, x1, x2: real;
begin
clrscr;
 write('nhap he so a='); readln(a); 
    write('nhap he so b='); readln(b); 
     write('nhap he so c='); readln(c);
  if a=0 then
    if b=0 then
      If c=0 then
        writeln('phuong trinh co vo so nghiem') 
      else writeln('phuong trinh vo nghiem')    
    else writeln('phuong trinh co mot nghiem: x=',-c/b: 4: 2) 
  else 
    begin
      d:=b*b-4*a*c;
      if d=0 then writeln('phuong trinh co nghiem kep: x=',-b/(2*a): 4: 2) 
      else
        if d<0 then writeln('phuong trinh vo nghiem')                      
        else                                                               
           begin
             x1:=(-b-sqrt(d))/(2*a);
             x2:=(-b+sqrt(d))/(2*a);
             writeln('phuong trinh co 2 nghiem la x1= ',x1:4:2 ,' va x2= ',x2:4:2); 
           end;
     end;
readln 
end.
9)
uses crt;
var c, r, d: integer;
begin
clrscr;
 write('nhap chieu dai: '); readln(c);
  write('nhap chieu rong: '); readln(r);
 writeln('chu vi hcn: ',(c+r)*2);
  writeln('dien tich hcn: ',c*r);
 d:=sqr(c)+sqr(r);
 d:=sqrt(d);
 writeln('do dai duong cheo: ',d);
readln;
end. 
10)
uses crt;
var a, h, s: real;
begin
clrscr;
 write('nhap canh day: '); readln(a);
  write('nhap duong cao: '); readln(h);
  s:=(a*h)/2;
  writeln('dien tich tam giac la: ',s:6:2);
readln;
end.
11)
uses crt;
var a, b: real;
begin
clrscr;
 write('nhap a, b: '); readln(a, b);
  if (a=0) and (b=0) then
  writeln('ptrinh vo so nghiem')
    else 
     writeln('ptrinh vo nghiem')
 else writeln('ptrinh co nghiem x= ',-b/a:6:2);
readln;
end.
12)
uses crt;
var a, b, r: integer;
begin
clrscr;
 write('nhap a: '); readln(a); 
  write('nhap b: '); readln(b);
  r:=a;
 a:=b;
 b:=r;
  writeln('sau khi trao doi a=',a,' b=',b);
readln;
end.
13)
uses crt;
var n, s, i: integer;
 a: array[1..1000] of integer;
begin
clrscr;
 write('nhap n: '); readln(n);
  for i:=1 to n do begin
  write('a[',i,']='); readln(a[i]);
    end;
     for i:=1 to n do
  if (a[i] mod 2<>0) then s:=s+a[i];
 writeln('tong cac so le trong day: ',s);
readln;
end.