RewriteEngine On
RewriteRule ^(.+)-([0-9]+)$ index.php?page=article&title=$1&id=$2 [QSA,L]
# OR if you might have other types of URLs that end with dash and numbers:
RewriteRule ^article/(.+)-([0-9]+)$ index.php?page=article&title=$1&id=$2 [QSA,L]