Bài 1 :

program tinh;
uses crt;
var x, y, z: real ;
begin
clrscr;
write(' nhap x:'); readln( x );
write(' nhap y:'); readln( y );
if (sqr(x) + sqr(y) <= 1)  then z:= sqr(x)+ sqr( y);
if (sqr(x) + sqr(y) > 1) and (y >= z) then z := x + y;
if (sqr(x) + sqr(y) > 1) and (y < z) then z := 0.5;
writeln('gia tri cua z la :', z:8:2  );
readln
end.

Bài 2 :

program dt;

uses crt;

var x, y, a, b, z, r  : real;

begin

clrscr;

write('nhap toa mot do diem  :');readln(x, y);

write('nhap toa do tam I :');readln(a, b);

write('nhap ban kinh r :');readln(r);

if r = sqrt(sqr(x - a) + sqr(y - b)) then z := abs(x) + abs(y)

else z := x + y;

writeln('gia tri cua z la :', z:8:2);

readln

end.

a)

uses crt;
var x,y:longint; z:real;
begin 
clrscr;
   write('Nhap x,y: ');readln(x,y);
   if x*x+y*y<=1 then z:=x*x+y*y else
   if (x*x+y*y>1)and(y>=x) then z:=x+y else
   if (x*x+y*y>1)and(y<x) then z:=0.5;
   writeln(z:0:2);
readln
end.

b)

uses crt;
var x,y,a,b,r:longint; z:real;
function kc(x1,y1,x2,y2:longint):real;
begin
   kc:=sqrt(sqr(x2-x1)+sqr(y2-y1));  
end;
begin 
clrscr;
   write('Nhap x,y: ');readln(x,y);
   write('Nhap r: ');readln(r);
   write('Nhap a,b: ');readln(a,b);
   if (kc(x,y,a,b)<r) then z:=abs(x)+abs(y) else z:=x+y;
   writeln(z:0:2);
readln
end.