Problem son and brilliant daughter- need some help?

First I would get him evaluated to see if he has a learning disability or not. If he doesn't I would look into getting him a tutor. See if that tutor can teach him in other ways. For example hands on activities etc. Stay involved! Its to bad you couldn't have sooner and have noticed his issues earlier especially if he has a learning disability such as Dyslexia or Language Learning Disability. Last you and your wife need to work together.