Bài 2: 

#include <bits/stdc++.h>;

using namespace std;

int main();

{

long m,n;

cout<<"Nhap m="; cin>>m;

cout<<"Nhap n="; cin>>n;

cout<<m*n-2;

return 0;

}

#include <bits/stdc++.h>

using namespace std;

long long a,b;

int main()

{

cin>>a>>b;

cout<<max(a,b);

return 0;

}

Program HOC24;

var a,b: integer;

D: longint;

begin

write('Nhap a: '); readln(a);

write('Nhap b: '); readln(b);

D:=2*(a+b);

write('D = ',D);

readln

end.

Chọn D

Khai báo biến a và b thuộc kiểu Integer

1:

uses crt;

const fi='ketqua.txt';

var f1:text;

st:string;

i,d:integer;

begin

clrscr;

assign(f1,fi); rewrite(f1);

write('Nhap xau:'); readln(st);

d:=length(st);

for i:=1 to d do 

 if st[i]=#32 then delete(st,i,1);

writeln(f1,st);

close(f1);

end.

2:

uses crt;

var a,b,c,d:integer;

{----------chuong-trinh-con-----------------------}

function min(x,y:integer):integer;

begin

if x<y then min:=x

else min:=y;

end;

{---------------chuong-trinh-chinh--------------------}

begin

clrscr;

write('a='); readln(a);

write('b='); readln(b);

write('c='); readln(c);

write('d='); readln(d);

writeln(min(a,min(b,min(c,d))));

readln;

end.

Câu 1: 

uses crt;

var a,b:integer;

begin

clrscr;

readln(a,b);

write(a+b);

readln;

end.

Câu 2:

uses crt;

var a,b,c:integer;

begin

clrscr;

readln(a,b,c);

writeln(a+b-c);

readln;

end.

Câu 3: 

uses crt;

var a,b:integer;

begin

clrscr;

readln(a,b);

writeln(a-b);

readln;

end.

Câu 4: 

uses crt;

var x,y,z:integer;

begin

clrscr;

readln(x,y,z);

writeln((x+y)*z);

readln;

end.