program pascal_p_primka;
var
  x1, y1, x2, y2, u1, u2 : real;

begin
  writeln('Zadejte souradnice bodu A[x1;y1], B[x2;y2] (desetinny oddelovac je tecka)');
  write('x1: ');
  readln(x1);
  write('y1: ');
  readln(y1);
  write('x2: ');
  readln(x2);
  write('y2: ');
  readln(y2);

  u1:=x2-x1;
  u2:=y2-y1;

  writeln('Parametricka rovnice primky:');
  writeln('x = ',x1:5,' + ',u1:5,'t');
  writeln('y = ',y1:5,' + ',u2:5,'t');
  readln;

end.