I am using the Twenty Twelve theme and have a child theme set up to make changes in. I have searched for how to hide these tags and have found various responses (ranging from editing php files to css files) for other themes but none have worked in Twenty Twelve.
I think the solution might be within the functions.php file but when I copy it to my child folder it crashes my site.
I would like to make these tags hidden, without compromising any search engine optimization.
Do not edit the Twenty Twelve theme. It is the default WordPress theme and having access to an unedited version of the theme is vital when dealing with a range of site issues. First create a child theme for your changes. Or use a custom CSS plugin.