How to add a variable with a URL inside of an if statement

Here is the code I wrote. The else is working. The if URL's are not.

<?php
if ( is_user_logged_in() ) {
    echo'<a href="$adminurl;" class="btn btn-primary">Set As Facebook Cover</a>';
    echo'<a href="$img[0];" class="btn btn-default">Download</a>';
} else {
    echo'<a href="http://ift.tt/1D0RMrK" class="btn btn-primary">Set As Facebook Cover</a>';
    echo '<a href="http://ift.tt/1D0RMrK" class="btn btn-default">Download</a>';
}
?>