Обратный элемент по модулю

"; if (isset($_POST['save_pupil'])) { $multiplicationС = stripinput(trim($_POST['multiplicationС'])); $modul = stripinput(trim($_POST['modul']));}echo "
\n"; echo "\n\n"; echo "\n"; echo "\n"; echo "\n\n"; echo "\n"; echo "\n"; echo "\n\n"; echo "\n"; echo "\n\n"; echo ""; echo "\n
Получен умножением на число С:"; echo ""; echo "
Приведён по модулю n:"; echo ""; echo "
\n"; echo "
\n"; echo "
\n";echo "
\n"; if($multiplicationС && $modul){ echo "
"; echo ""; echo ""; echo ""; echo ""; echo ""; echo ""; echo ""; echo "
 "; $obratn = inverse($multiplicationС, $modul); echo "Обратный элемент = $obratn
"; ""; echo "
";}require_once THEMES."templates/footer.php";?>