You can use this snippet. Just make sure you change the widget id :
<?php
add_filter( 'widget_display_callback', 'widget_display', 50, 3 );
function widget_display( $instance, $widget, $args ){
if ( is_page() && $widget->id == 'text-39' ) {
return false;
}
return $instance;
}
?>
The easiest way is to use a WordPress plugin though. There are lots of free plugins on the directory. I would highly recommend Widget Options : https://wordpress.org/plugins/widget-options/ . Check the image below for integration preview.
Cheers!