var query =
    from area in _context.areas
    where area.IsAuxiliar == getAreasDto.IsAuxiliar
    join service in _context.services on area equals service.Area into servicesByArea
    select new GetServicesCountByArea
    {
      AreaDescription = area.Description,
      ServicesCount = servicesByArea.Count(),
      AreaId = area.Id
    };