Program hoan_doi;

uses crt;

var hd p ,q: integer;

begin

clrscr;

write('nhap p ='); readln(p);

write('nhap q ='); readln(q);

write('gia tri ban dau cua p = ',p,' va ' q = ',q);

hd:=p;

p:=q;

q:=hd;

writeln;

writeln('gia tri cua p va q sau khi hoan doi la p =',p,' va q =',q);

readln;

end.

2.

-lệnh dùng để xóa màn hình làm việc:

Uses Crt ; { khai báo thư viện hàm }

Clrscr; { lệnh xóa màn hình kết quả }

- hai lệnh này dùng song song vs nhau nha.

VD:

Program vi_du;

uses crt;

var i,n: integer;

s: real;

begin

clrscr;

write('nhap so n ='); readln(n);

s:=0;

for i:= 1 to n do

s:=s+i;

writeln(s :4:2);

readln;

end.

-lệnh dùng để xóa màn hình làm việc:

Uses Crt ; { khai báo thư viện hàm }

Clrscr; { lệnh xóa màn hình kết quả }

- hai lệnh này dùng song song vs nhau nha.

VD:

Program vi_du;

uses crt;

var i,n: integer;

s: real;

begin

clrscr;

write('nhap so n ='); readln(n);

s:=0;

for i:= 1 to n do

s:=s+i;

writeln(s :4:2);

readln;

end.

ƯCLN ( 13 ; 12 ) = 1

tick nha

Program Chuoi_Chu_Thuong;
Uses Crt;
Var i,l:integer;
st:string[50];

Begin
Clrscr;
Writeln(‘DOI CHUOI SANG CHUOI CHU THUONG’);
Write(‘Nhap chuoi ky tu: ‘); Readln(st);
For i:=1 to length(st) do
If (st[i]>=’A’) and (st[i]<='Z') then st[i]:= chr(ord(st[i])+32);
Writeln;
Writeln('Chuoi doi thanh chu thuong la : '); Writeln(st);
Writeln; l:=length(st); st[l]:=upcase(st[l]); For i:=l downto 2 do
If st[i]=' ' then st[i-1]:=upcase(st[i-1]);
Writeln('Chuoi cac ky tu cuoi cua tu la ky tu hoa: ');
Writeln(st);

Readln;

End.

Program Đổi_Tiền;

var

loai5000,loai2000,loai1000,m,n: integer;

write('nhap so tien can doi :'); readln(n);

M:=n;

loai5000:= n div 5000; n:=n-loai5000*5000;

if n<>0 then

begin

loai2000 :=n div 2000; n:=n-loai2000*2000;

if n<>0 then

begin

loai1000:=n div 1000 ; n:=n-loai1000*1000;

end;

writeln(M , 'doi duoc thanh :' ,loai5000,' to 5000,' ,loai2000,' to 2000 ,' ,loai1000,' to 1000 ,');

readln;

end.

7.

program pt ax+b=0;
uses crt;
var a, b: logint;
Begin
write('nhap so a ='); Readln(a);
write('nhap so b ='); readln(b);
If (a = 0 and b = 0)
then write ('pt co nghiem x thuoc R')
else
if (a=0 and b#0) then write('pt vo nghiem')
else
write(nghiẹm la x=': -b/a);
readln
end.

câu 4,5,6.

program tam_giac;

uses crt;

var a,b,c: real;

begin

clrscr;

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

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

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

if ( a+b < c) or ( a+c < b) or ( b+c < a) then

write('khong phai ba canh cua tam giac ') else

if ( a=b) and (b=c) then writeln('la tam giac deu ') else

if (a=b) or (b=c) or (c=a) then writeln('la tam giac can ') else

if (a*a=b*b+c*c) or (b*b=a*a+c*c) or ( c*c=a*a+b*b) then

writeln('la tam giac vuong') else

writeln('khong phai so do 3 canh cua tam giac deu ',' tam giac can ',' tam giac vuong');

readln;

end.

2.

program bai2 ;

uses cer;

var a,b,c,d,max: integer;

begin

clrscr;

write('nhap so thu nhat ='); readln(a);

write('nhap so thu hai ='); readln(b);

write('nhap so thu ba ='); readln(c);

write('nhap so thu tu ='); readln(d):

max:=a;

if max > b then write('so lon nhat la so ',a,' ') else

write('so lon nhat la so ',b,'');

if max > c then write('so lon nhat la so ',a,' ') else

write('so lon nhat la so ',c,' ');

if max > d then write('so lon nhat la so ',a,' ') else

write('so lon nhat la so ',d,'');

readln;

end.

abcd  =x²

abcd - 1111 =y² => x ² - y² = 1111

                           (x+y(x-y) =101.11  = 1111.1

+ x+y =1111 ; x -y =1 => x =556 ; y = 555  => x² = 556² =309136 loại

+ x+y = 101 ; x -y =11 => x = 90 ; y =79  => x² = 8100 (TM)

vậy A =8100