Display Some text in some specific category not all category

Place this code in single.php where you need to show it:

<?php 
$catarray = get_the_category( $post->ID );
foreach ($catarray as $cat) {
    $catid = $cat->term_id;

    if ($catid == 5) {
      echo 'TEXT HERE';
    }
    if ($catid == 7) {
      echo 'ANOTHER TEXT';
    }

}
?>