Câu 2 :
program bai2;
uses crt;
var n :integer;
begin
clrscr;
writeln(' ');
writeln(' TIM GIA TRI TUYET DOI CUA MOT SO');
writeln(' ');
write(' Ban hay nhap so n = ');
readln(n);
if n>0 then writeln('Gia tri tuyet doi cua ',n,' = ',n);
if n<0 then writeln('Gia tri truye doi cua ',n,' = ',n*-1);
readln
end.