Syntax error comes from your js file that is containing php code. You don’t need this part to be in the js file and need to be in a php file.
<?php
function form_ajax_process_request() {
if( isset( $_POST["post_var"] ) ) {
$response = $_POST["post_var"];
echo $response;
die();
}
}
add_action('wp_ajax_form_response','form_ajax_process_request');
add_action('wp_ajax_nopriv_form_response','form_ajax_process_request');
?>
This part need to be in school_core.php
(without <?php and ?>
).