Hide activities and show posting form only

shortcodefree-posting-form.php

/**
<?php
* Wbcom shortcode activity
 *
 */
add_action('wp_head','wbcom_shortcode_activity_hide');
function wbcom_shortcode_activity_hide(){
    global $post;
    if( has_shortcode( $post->post_content, 'activity-listing' ) ){      
    ?>
    <style>
        .activity ul,
        .activity .activity-list{
            display:none;   
        }
    </style>
    <?php
    }
}
?>