Hiding category from Blog Home Page

Hi.
We run a tech blog using WordPress and want to hide posts from certain category on the homepage. My theme developer replied to my email saying...
====
For this you would need to modify the WP_Query function in the file \functions\newstrick-blog-widget.php
http://codex.wordpress.org/Class_Reference/WP_Query#Category_Parameters
====
I checked the link and found this for my need.
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$query = new WP_Query( 'cat=-12,-34,-56' );
====
But I do not know where to add this line in my file below.

}
   
    function widget($args,$instance){
        extract($args);   
 
        global $data, $post, $wp_query, $query;
 
        $ct_num_blog_posts = $instance['ct_num_blog_posts'];
        //$categories = $instance['categories'];
        $title = $instance['title'];
        $pagination_type = $instance['pagination_type'];
 
        $show_image = isset($instance['show_image']) ? 'true' : 'false';
        $show_likes = isset($instance['show_likes']) ? 'true' : 'false';
        $show_comments = isset($instance['show_comments']) ? 'true' : 'false';
        $show_views = isset($instance['show_views']) ? 'true' : 'false';
        $show_date = isset($instance['show_date']) ? 'true' : 'false';
        $show_category = isset($instance['show_category']) ? 'true' : 'false';
        $excerpt_lenght = $instance['excerpt_lenght'];
        $video_height = $instance['video_height'];
        $widget_width = $instance['widget_width'];
        $background = $instance['background'];
        $background_title = $instance['background_title'];
        $divider_type = $instance['divider_type'];
 
        // Get number of posts to display from Theme Options
        $blog_num_posts = stripslashes( $data['ct_blog_num_posts'] );
 
        $max = 0;
        $count_posts = wp_count_posts();
        $ct_post_count = $count_posts->publish;
        $max = ceil ($ct_post_count / $blog_num_posts);
 
        /* Before widget (defined by themes). */
        if ( $title ){
            echo "\n<!-- START BLOG WIDGET -->\n";
            echo '<div class="' . $widget_width . '"><div class="widget ct-blog-widget margin-30t box border-1px bottom-shadow clearfix" style="background:' . $background . ';">';
            echo '<div class="widget-title bottom-shadow" style="background:' . $background_title .';"><h2>' . $title . '</h2><div class="arrow-down" style="border-top-color:' . $background_title . ';"></div><!-- .arrow-down --><div class="plus"><span></span></div><!-- .plus --></div><!-- widget-title -->';
        } else {
            echo "\n<!-- START BLOG WIDGET -->\n";
            echo '<div class="' . $widget_width . '"><div class="widget margin-30t box border-1px bottom-shadow clearfix" style="background:' . $background . ';padding-top: 20px;">';
        }
               
        ?>
 
        <?php
 
        if ( get_query_var('paged') ) {
              $paged = get_query_var('paged');
        } elseif ( get_query_var('page') ) {
              $paged = get_query_var('page');
        } else {
              $paged = 1;
        }
 
 
        if ( !function_exists( 'ct_blog_pagination' ) ) {
            function ct_blog_pagination($pages = '', $range = 4)
            { 
                $showitems = ($range * 2)+1; 
 
                global $paged;
                if(empty($paged)) $paged = 1;
 
                if($pages == '')
                {
                    global $wp_query;
                    $pages = $wp_query->max_num_pages;
                    if(!$pages)
                    {
                        $pages = 1;
                    }
                } 
 
                if(1 != $pages)
                {
                    echo "<div class=\"pagination clearfix\"><span>Page ".$paged." of ".$pages."</span>";
                    if($paged > 2 && $paged > $range+1 && $showitems < $pages) echo "<a href='".get_pagenum_link(1)."'>&laquo; First</a>";
                    if($paged > 1 && $showitems < $pages) echo "<a href='".get_pagenum_link($paged - 1)."'>&lsaquo; Previous</a>";
 
                    for ($i=1; $i <= $pages; $i++)
                    {
                        if (1 != $pages &&( !($i >= $paged+$range+1 || $i <= $paged-$range-1) || $pages <= $showitems ))
                        {
                            echo ($paged == $i)? "<span class=\"current\">".$i."</span>":"<a href='".get_pagenum_link($i)."' class=\"inactive\">".$i."</a>";
                        }
                    }
 
                    if ($paged < $pages && $showitems < $pages) echo "<a href=\"".get_pagenum_link($paged + 1)."\">Next &rsaquo;</a>"; 
                    if ($paged < $pages-1 &&  $paged+$range-1 < $pages && $showitems < $pages) echo "<a href='".get_pagenum_link($pages)."'>Last &raquo;</a>";
                    echo "</div>\n";
                }
            }
        }
 
 
        // Check if Load More Button
        if ( $pagination_type == 'load_more' ) :
            wp_enqueue_script(
                'pbd-alp-load-posts',
                get_template_directory_uri() . '/js/load-posts.js',
                array('jquery'),
                '1.0',
                true
            );
 
            // Add some parameters for the JS.
            wp_localize_script(
                'pbd-alp-load-posts',
                'pbd_alp',
                array(
                    'startPage' => $paged,
                    'maxPages' => $max,
                    'nextLink' => next_posts($max, false)
                )
            );
        endif;
 
        $recent_posts = new WP_Query(array(
            'posts_per_page' => $blog_num_posts,
            'paged' => $paged,
            'post_type' => 'post'
            //'cat' => $categories

PHP:

Can someone please help.

Thanks in advance.

 

What file are you showing right there? If you give me the filename I may be able to help you out.

 

If youre trying to display posts from only those categories, depending on where you want them, I'd say you need to make a new template page and find the similar code in that page or the and replace it.

Something similar to this:
http://wordpress.org/support/topic/show-posts-of-a-certain-category-on-a-page
Read the last post there. There's a WP_query code near the top of the code that user posted.

Here's the code I'm referring to.
<?php $paged = (get_query_var('paged')) ? get_query_var('paged') : 1; $the_query = new WP_Query('cat=36&paged='.$paged.'&showposts=30&orderby=post_date&order=desc'); while ($the_query->have_posts()) : $the_query->the_post(); $do_not_duplicate = $post->ID; ?>