Sometimes Google Scholar has two different versions of the same articles. You can merge two or more articles together. On the "My Citations" screen check the box next to the articles you wish to merge.
On the top menu select "Merge"

You will then see screen which asks which article is the most up-to date. Choose your selection and select "merge".

Not only will this erase duplicates, it will also merge citations, deleting overlaps. For example if one article was cited 60 times and another 40 times, but after the merge the total number of citations was 90, this indicates that 10 papers cited both of these articles.