does any one know how do borrar a spam image from an group?

Well, it takes a while for a spam image to go away but I could reportar it, too if tu like? :)

Post the link, and people will reportar it, too. This may help to make it quicker.

Reporting the image itself usually gets it removed quite quickly. Reporting the member who publicado it can get that account closed, especially if they spam repeatedly. I don't know whether más than one person needs to reportar for this to work though - I know that's needed for broken videos and links, but not whether the same applied for all reports.