Warning: Undefined variable $busca in /home/mk000517/public_html/notas.php on line 7

Warning: Undefined variable $q in /home/mk000517/public_html/notas.php on line 9

Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, null given in /home/mk000517/public_html/notas.php:9
Stack trace:
#0 /home/mk000517/public_html/notas.php(9): mysqli_num_rows(NULL)
#1 {main}
  thrown in /home/mk000517/public_html/notas.php on line 9