1.

program ct;
uses crt;
var i:Qword;
begin
  clrscr;
  writeln('Nhap so Kwh: ');readln(i);
  writeln('So tien dien la: ',i*1500,'đ');
  readln;
end.

2.

program ct;
uses crt;
var a,b:integer;
begin
  clrscr;
  writeln('Nhap so a, b: ');readln(a,b);
  writeln(a,' + ',b,' = ',a+b);
  readln;
end.

3.

program ct;
uses crt;
var HoTen: string;
    NamSinh: Qword;
begin
    clrscr;
    writeln('Nhap Ho va Ten: '); readln(HoTen);
    writeln('Nhap nam sinh: '); readln(NamSinh);
    writeln('Tuoi hien tai cua ban ',HoTen,' la: ',2021-NamSinh);
    readln;
end.

4.

program ct;
uses crt;
var a,b,c:integer;
begin
  clrscr;
  writeln ('Nhap TBM của môn Toán, Lý, Hóa: '); readln(a,b,c);
  writeln ('Diem trung binh 3 mon tren la: ',(a+b+c)/3:5:2); 
  readln;
end.

5.

program ct;
uses crt;
var a,b:int64;
begin
  clrscr;
  writeln ('Nhap so nguyen a,b: '); readln(a,b);
  writeln ('Tong cua a^2 va b^2 =', a*a+b*b);
  readln;
end.

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#Duahauvn