I think it's the other way around with adwords. (google makes adds, you pay google if people use them)

But to let people find you in x5 through google use in the properties of the page's keywords and description:

http://help.websitex5.com/en/v13/pro/mappa_pagina_tab1.htm

http://help.websitex5.com/en/v13/pro/advert_ht.htm

please search the help, there are more items there in regard of working with google.